ɪn nˈaɪntiːnhˈʌndɹɪd nˈaɪnti sˈɪks hˈeɪz fˈɔːɹmd ɐn ɐkˈuːstɪk dˈuːoʊ wɪð dˈɛnɪs kˈæhɪl, dɪvˈɛləpɪŋ æn "ʌnɹˈʌʃt, lˈɪɹɪkəl, hˈaɪli ɛkspɹˈɛsɪv ɪntˌɜːpɹɪtˈeɪʃən" ʌv tɹɐdˈɪʃənəl ˈaɪɹɪʃ mjˈuːzɪk.
In 1996 Hayes formed an acoustic duo with Dennis Cahill, developing an "unrushed, lyrical, highly expressive interpretation" of traditional Irish music.