Curating and annotating a collection of traditional Irish flute recordings to facilitate stylistic analysis

In the Irish tradition, the term ‘tune’ is used to refer to a melody that is usually composed of parts that may be repeated a number of times. Most tunes contain two parts and tunes with more parts are less common [7].

In the example shown in Fig. 1, each tune has two parts, denoted as an ‘A’ and a ‘B’, typically containing eight bars of music in each. Very often a performer will choose three such tunes, usually in different key signatures, which are performed as a continuous piece of music, referred to as a ‘set of tunes.’ This is, in part, influenced by the desired length of a track, usually lasting three to four minutes. It is important that each tune in a set is identified. It may be noticeable that while some stylistic features, such as phrasing, are consistent, some ornaments may be used more or less regularly in different key signatures.

The titles of tunes within Irish traditional music often make reference to interesting facets of everyday life, taking their name from people, geographical locations or common undertakings, pastimes or situations [19, 23, 62]. Jim Donoghue’s, Maurice O’Keeffe’s and McGivney’s Fancy refer to specific people, while the protagonists in The Girl in the Big House, The Kerry Man and The Maid on the Green remain nameless. Groups of people from a particular area are commonly referred to as lads, lasses or maids as shown in Maids of Ardagh. Natural history is also popular as a subject area, with plants such as The Hawthorn, The Ashplant and The Flax in Bloom and animals like The Hare in the Heather and The Pigeon on the Gate. Geographical locations like The Humours of Ballyloughlin and The Church Street Polka are popular. While occasionally tunes have titles like the Edenderry Reel or the Church Street Polka, Hast and Scott [23] note that most titles do not describe the type of tune.

The annotated recordings contain a number of tune types, namely Jigs, Reels, Hornpipes and Polkas. Many tunes had migrated from England and Scotland and underwent a process of being consolidated into Irish traditional music corpus over the eighteenth and nineteenth centuries [51]. According to O’Connor [49], most of Irish traditional music played now is dance music, but is more commonly played for listening. The music is “inextricably linked to dance” and can be characterised by its metric structure or the number of beats per measure [11, p. 90].

Playing tempo is generally defined by context. The origins of Irish traditional music lie in accompaniment of dancing during the eighteenth century, separating into its own concert tradition in America and Ireland during the nineteenth century [49]. This allowed tunes to be played at tempos which would not be suitable for dancing, but are effective on the concert stage.

It is unusual to find Irish traditional music played ‘straight’ or with all eighth notes identical in duration. Pairs of eighth notes in reels and hornpipes will often be ‘swung’ with a longer first note and a shorter second note. Rosinach and Traube [55] define swing as a ratio of these long and short note durations, where (1:1) is no swing and (3:1) is hard swing. They found that ratios of around (2:1) are common within Irish music. Larsen notes that classically trained musicians often find this swing or ‘lilt’ initially difficult to grasp because it is learned by immersion rather than analysis [38].

The flutes played in the recordings chosen for this corpus are mostly wooden pre-Boehm transverse flutes, the most popular choice of flute in Irish traditional music [17, 22, 60]. Most of the instruments are tuned with a lowest note D and measure approximately 60–68 cm in length, with a bore diameter of approximately 3 cm narrowing to 2.5 cm at the end farthest from the blow hole. Most have six primary open finger-holes, but many have up to eight keys² to allow the musician to more easily play passages that might otherwise require complex cross-fingering patterns. While flutes played in the tradition can date back to the eighteenth century, a number of instrument makers have been making instruments targeted at Irish traditional musicians since the late 1970s [17, 60].

In Irish traditional music, ornaments are used as embellishments of the melodic line [38]. On the flute, they are usually created through the use of special fingered articulation. Their places are mostly not marked in the score, and the choice of their usage usually depends on performer’s style. Ornaments can be categorised as single-note and multi-note ornaments.

The musicians chosen for inclusion in this project represent a wide spread of geographical areas born between 1925 and 1974. At the outset of this project, four flute players were identified as a starting point for the study of style in Irish traditional music: John McKenna, Séamus Tansey, Matt Molloy and Harry Bradley. Additional flute players have also been added including Josie McDermott, Michael Tubridy, Catherine McEvoy, Conal Ó Gráda and John Wynne. The selection of recordings spans from 1921 to 2014 and include recordings made in both Ireland and the USA. The influence of some of the older recordings on the younger generation is widely noted in the sleeve notes and various articles quoting the younger musicians (see e.g. [50]). Despite trends of globalisation, international popularity and technological developments that have changed how music is shared and consumed, in many instances, Irish traditional music retains a sense of local and regional identities that are, in some instances, related to musical styles [30]. While Keegan has chronicled the difficulties in developing a definitive treatise on Irish traditional flute styles [33], the diversity of styles within the tradition remains part of the richness of the soundscape of Irish traditional music. The development of a discourse on musical style in Irish traditional music and the relationship between styles and regional traditions owes much to Seán Ó Riada’s seminal 1962 radio series Our Musical Heritage [54]. Included in this study are two of the flute players, Michael Tubridy and Séamus Tansey, who featured in the series. The role and influence of North Connacht flute players on flute styles in Irish traditional music is also evident in a critical consideration of the musicians chosen for inclusion in the digital library.

Clare is often considered a core place in Irish musical traditions. Located on the west coast of Ireland (see Fig. 3), its reputation in the context of Irish traditional music has been widely written about, see for example [25, 51]. Michael Tubridy was born in Kilrush in Co. Clare into a musical household in 1935 [60, p. 696–697] and active in the Dublin music scene from the 1960s. Describing Tubridy as ‘a perfect example of the Clare style’, Ó Riada describes the Clare style as ‘a rolling ornamented style, and this combined with the regular phrasing and discreet rhythm, gives it a level, even character’ [54].

Many early recordings of Irish traditional music were made in the USA. Leitrim-born John McKenna (1880–1947) was the most prominent flute player to record in America in the early years of commercial recording. In all of the forty-four tracks recorded by McKenna, he is accompanied by other musicians.³ For the purposes of the archive, tracks that feature just McKenna and a piano accompanist (who is merely playing or ‘vamping’ chords) have been selected for future inclusion. Bradshaw notes ‘He recorded many polkas, particularly on his duet recordings, and he is renowned for the breathy, rhythmic style of north-east Connacht’ [60, p. 442]. A recent compilation of McKenna’s recordings [21] includes forewords by Matt Molloy and Conal Ó Gráda, both of whom provide source material for this study and de Barra notes his influence on Tansey, Molloy, Ó Gráda and Bradley in his study of Irish traditional flute playing [17].

Flute playing in Irish traditional music is often associated with the North Connacht region, which includes counties Sligo, Roscommon and Leitrim. Sligo achieved much attention in the early decades of the twentieth century, due in no small part to the success of fiddle players who emigrated from the area to America and became part of the recording industry there. Chief among these were Michael Coleman (1891–1945), Paddy Killoran (1904–1974) and James Morrison (1893–1947), who played in distinctive but related, highly ornamented styles. Ó Riada suggested that the fiddle and flute styles of Sligo were related, although the flute playing was less ornamented, highlighting Peter Horan (1926–2010) as a flute player of note [54]. We include two Sligo born musicians. Josie McDermott (1925–1992) was born in Co. Sligo near the Roscommon border and played a wide range of music and sang, drawing on influences from the popular music of the time. Séamus Tansey was born at Gurteen, Co. Sligo to a musical family in 1943 [60, p. 676–677]. Starting on the tin whistle, Tansey learned informally from local musicians before moving to County Armagh.⁴

Matt Molloy (b. 1947), Catherine McEvoy (b. 1956)⁵ and John Wynne (b. 1970)⁶ all have roots in Roscommon and are influenced by the North Connacht tradition of flute playing. Wynne notes that the use of the flute in the region ‘likely descends from the nineteenth century prevalence of marching band practices in Connacht’ [60, p. 581]. Molloy was born at Ballaghdereen, Co. Roscommon [60, p. 458] and influenced locally by whistle player Jim Donoghue, later moving to Dublin where he performed with a range of notable musicians. Larsen [38] describes Molloy’s approach to ornamentation as being ‘very dense and dramatic, it is also judicious, perfectly complimenting his long, smooth phrasing... [and has] intense forward motion’.

Cork is the largest county in Ireland with both rural and urban scenes. Cork Pipers’ Club, revived in 1963, has had a significant influence on the transmission of music in the area and developed links to Tralibane in West Cork, home of collector and flute player Captain Francis O’Neill [60, p. 167–168]. Cúil Aodha home of Conal Ó Gráda is located in the Gaeltacht. Ó Gráda was born at Ballincollig, Co. Cork in 1961, and his early influences include Mícheál Ó Riabhaigh of the Cork Pipers’ Club [60, p. 515]. He was later mentored by Clare flute player Séamus MacMathúna and achieved success in competitions. He is now based in Cúil Aodha, a Gaeltacht region in County Cork. In Companion to Irish Traditional Music [60], fellow flute player Hammy Hamilton notes that Ó Gráda’s style is ‘unmistakable’, described as ‘aggressive’, ‘driving’ and ‘rhythmic’ [60, p. 515]. His repertoire and style includes influences from the Sliabh Luachra region, noted for its repertoire of slides and polkas. His use of glottal stopping for articulation is noteworthy.⁷ Other flute players including flute maker Hammy Hamilton from Belfast also reside there. Ó Gráda and Hamilton together founded Crinniú na bhFlúit (‘the flute meeting’) in 2006, providing spaces for instrumental classes and discussion relating to the flute in Irish traditional music. While Irish traditional music is often associated with rural areas, Dublin and Galway city are significant spaces in Irish traditional music. Both urban areas provide many venues and session spaces. Dublin drew many rural migrants in search of employment in the mid-twentieth century and provided the incubation space for groups and bands to develop [27]. These cities attract large number of tourists whose interest and patronage of Irish traditional music contributes to the vitality of the tradition and related spaces, particularly public houses. Belfast-born Harry Bradley (b. 1974) was initially influenced by popular Irish groups such as Planxty and the Bothy Band and has spent time living in Cork, Dublin and Galway.⁸ He is also influenced by recordings of Irish traditional music from the 1920s and 1930s. Speaking about his musical style:

I suppose it’s a rhythmic style defined by laying down accented rhythms with pulses in the breathing [...] Also, it was always a thing in Belfast to play with a good tone and get a big sound out of the flute... there might have been a dozen flutes in some of the Belfast sessions, so we had to be able to hear ourselves. [57]

Other Belfast flute players include Noel Lenihan, Michael Clarkson, Sam Murray and Brendan O’Hare leading to some observers to propose a ‘Belfast style’ of flute playing.

We also include recordings of some flute tutors developing an awareness of how style is represented. One example of this is Grey Larsen (b. 1955), a well-known performer, flute maker and author of The Essential Guide to Flute and Tin Whistle [17]. Growing up in Cincinnati, Ohio, USA, he studied early music at two conservatories while, learning Irish traditional music from elder Irish immigrant musicians, most notably Co. Galway melodeon player Michael J. Kennedy (1900–1978), Co. Sligo flute player Tom Byrne (1920–2001) and Co. Leitrim fiddler Tom McCaffrey (1916–2006) [39]. The CDs accompanying his book include a range of traditional tunes as well as exercises showing a deep understanding of ornamentation and teaching techniques.

The corpus of audio recordings currently consists of 79 tunes from 11 players, who are introduced in Sect. 4.1. The tunes come from 12 commercially released CDs. Table 1 gives the list of the CDs, indicating the players and tunes selected. The tunes were specifically selected with the aim of having audio with no (or minimal) accompaniment. The original recordings are in uncompressed wav format, stereo, sampled at 44.1 kHz with 16 bits per sample. These are converted into monophonic signal, by summing the signal in both channels. For each of the 79 tunes, the first repetition⁹ in the tune (see Sect. 2.1) was extracted from the audio and stored. In addition to this, we also extracted second/third repetitions from some of the tunes, in total 20. Therefore, there are 99 audio files with annotations in total. All presented analyses in the following sections are based on the set of 79 tunes without the additional repetitions in order to avoid an artificial bias due to the repetitions.

Table 2 gives the statistics of the types of tunes played by each player. It can be seen that jigs and reels are the most common tune types shared by most of the players in our collection, while hornpipes and polka are played only by three and two players, respectively.

The total length of annotated audio is over 40 mins, and this contains 11,991 notes, 1603 single-note and 776 of multi-note ornaments.

Table 3 gives the statistics for each player, specifically, the key of the flutes used, the number of notes and single- and multi-note ornaments for each player, with the total duration of annotated audio. The flutes played on the recordings include flutes pitched in different keys. The most common is the D flute. However, there are several reasons a player may play a flute in a different key. Within the corpus, both Harry Bradley and Matt Molloy play flutes in Eb, F and Bb. The Eb and F flutes are higher pitched than D flute and as such they can provide a brighter sound. Matt Molloy’s Bb flute is lower in pitch than a concert D flute and will therefore give a more mellow sound.

Table 4 gives the set of notes present for each key of flute present in our corpus. While the ‘standard’ flute is D, a player will refer to any transposing flute as if it is in the key of D. The note name is always taken from the finger positions covering the holes, e.g. covering the top three holes on a D flute would result in the note of G. A player asked to play a G note while holding an F flute would still cover the top three holes. The actual note produced would be a Bb.

The purpose of manual annotation of the audio data was to provide for each tune information on the onset of notes, the pitch of notes and the presence and type of ornamentation. The annotation was performed by an experienced player of Irish traditional flute.

This section provides an initial quantitative response to the ethnomusicological questions that are usually addressed in a qualitative manner and which are sometimes undermined by perceived subjectivity. This is performed through a variety of statistical analysis of the audio data obtained based on the manual annotation. Specifically, we present analysis of duration of notes and ornaments, quantity of ornamentation used by various players and analysis of note sequences. This information provides some pointers towards the study of style as well as it would be useful for development of an automatic system to analyse the audio, e.g. [24, 36]. For instance, the durations of notes and ornaments can be exploited in designing a suitable temporal filtering operations for detection of onsets and ornaments and the knowledge of note sequences in an automatic transcription system as a prior probability of the note following the current note.

Along with the manual annotation, we have conducted research on methods for music information retrieval, specifically to detect onsets and ornaments and estimate note frequency in a view to obtain annotation of the tunes automatically. In this paper, we present the results of onset detection obtained using two conventional onset detection algorithms, which is to serve as a baseline for future research in this area. Both methods exploit the change of the signal amplitude over time, with processing performed in the temporal and spectral domain. The description of these methods, which we also used in our previous onset detection research, is provided in [36].

We performed extensive evaluations with different parameter values for each of these conventional onset detection methods. The best achieved performance for each of the methods is presented in Table 6. It can be seen that they both perform similarly, achieving the F-measure of over 81%.