The tonic sol-fa system is, for me, absolutely indispensable. I can hear any song, any melody, and instantly (like simultaneously) transfer it, in real time, in my head into tonic sol-fa... accidentals and all.

This is an immense help when it comes to working out accompaniment on the guitar ...you just know instinctively which chord goes where ...

It is even more useful when it comes to working out leads on the guitar ...if you know the different scale positions on the fretboard, then you know where doh, ray, mi, fah, so, lah, ti, doh lie for that particular key.

I will give credit here to my boyhood friend William Graham, who was taught the tonic sol-fa system in primary (grade) school as a child in Lochinver, a lovely village on the north west coast of Scotland.

William and I were room-mates in the boarding house where we both lived while we acquired our higher education, and I was amazed by his ability to instantly sing any song you threw at him in tonic sol-fa. His party piece was "The Irish Washerwoman" sung in rapid fire tonic sol-fa. I swore to myself that I would one day acquire this skill, and eventually I did.

FWIW, William became in later years the father of the Mod Gold medallist James Graham, a wonderful young Gaelic singer who has also appeared on Transatlantic Sessions (Series 4 IIRC). James, however, was never taught the tonic sol-fa system, so I suspect that William and I may well be the only two people on the planet in possession of this rather arcane skill.

I would absolutely love to hear from anybody else who is able to do this instantaneous tonic sol-fa conversion.