Bb Valve Trombone to C

[SFA]

I believe this requires 12" to be removed at the main tuning slide (6" each leg) but I have no idea what happens at the
1st, 2nd & 3rd valve tuning slides. How is this calculate please.

[ithinknot]

Basically, per leg it's 6" in the cylindrical TS, 3/4 for the 1st valve, 3/8 for the 2nd, and 1 1/8 for the 3rd.

If you're interested... the equal temperament semitone ratio is 1:2^(1/12), thus 2^(2/12) for a whole tone, very close to the just major tone ratio of 9:8.

	Bb	C	difference	per leg
open	108	96	12	6
1st	13.226	11.756	1.470	0.735
2nd	6.422	5.708	0.714	0.357
3rd	20.434	18.164	2.270	1.135

[SFA]

THANK YOU. THAT'S GREAT.