Thanks so much, Alastair. I play a few different pieces by Bach and I can't quite recall what I played in Sligo, but I'm guessing you're referring to the prelude from the first suite for unaccompanied cello? That's a bit of a long story so I hope you'll bear with me!
Like so many of us, I've enjoyed working with those cello suites for many years and it's been fun trying out different formats -- tunings, fretless/fretted, using the double bass transcriptions or the originals, etc. That first prelude is probably most famous in its transcription for guitar and my old friend Michael Hedges used to do a wonderful version on his harp guitar, using the bass strings to get the low C from the original. I loved hearing his hippie romantic interpretation of it and when Michael died I was really quite sad to think I'd never get a chance to hear that particular spirit again. So to make myself feel better, I decided to work on it a bit and in going through it I realized I liked the way the fretted bass allowed me to allude to the guitar version. I also realized that by tuning in fifths and using a capo I could play it in the original key, register and with many of the original fingerings. I like to play it more slowly and dramatically than most folks, because it makes me think of Michael and all the memories I have. The combination of these interpretive options make it something quite meaningful for me, and I enjoy playing it a shows once in a while.