from Edward Bunting, The Ancient Music of Ireland (Dublin 1840), Page 26: Double notes, chords, etc. for the right hand.
spoken by Gráinne Yeats
Scottish Gaelic glas spoken by Tony Dilworth
Click the play button to hear it spoken. help
“By thumb and third finger, an octave.”
Simon Chadwick 2008
Glas is the first item under the heading "Double notes, chords, etc. (...) For the right hand" on page 26. When played as a descending sequence as printed by Bunting on a Gaelic harp, the long resonance of the bass strings makes this figure musically unusable. We might follow Ann Heymann in assuming Glas became confused with Ladhar; we could play ascending octaves by playing 1 and 3, sliding the thumb to damp the note below that which it sounds, while damping/placing with 2 and 4 adjacent to the string sounded by 3 (or in Bunting's system, play + and 2, place 1 and 3). This is Ann's "Combination technique" as explained in her books Coupled Hands for Harpers (2001) and Secrets of the Gaelic Harp (1988). The video clip shows both.
Glas is unique for appearing with the same Irish spelling, and the same translation, in both the left (treble) hand, and in the right (bass hand) however the musical examples differ.
Simon Chadwick 2004
Glas - A joining
This must be glas, the normal Irish word for 'a lock' (as on a door); to be distinguished from the glass appearing in Tead a' leithghleas above.
See also Glas (for the left hand).
Colm Ó Baoill 2002