I found the recent thread about covering the Bass Trombone part on a Tenor Trombone very interesting – it is both a challenge that I might take on at some point and learning how to make the instrument play well and through the trigger in the lower range is an interesting development of playing skill – however the ‘conversation’ centred around mouthpiece choice to use with an existing instrument. It didn’t seem completely fair to add on to the other thread (http://www.themouthpiece.com/vb/sho...e-players-covering-bass-parts-on-a-tenor-HELP!) so I’ve started this new one in the hope that it will produce some useful comments on the large bore tenor and maybe the single trigger bass too. What features make a (large bore?) Tenor Trombone more or less suitable for playing the Bass Trombone part? In response #3 of the earlier thread Dave Taylor did mention how very well Simon Cowen had played Bass Trombone for Staines at the area Championship Section on a Conn 88H (CL version?), so it can be done well with the right instrument. However, would it have worked as well on a Bach 42 with a standard valve and closed wrap? I’ve ready many comments elsewhere in which players felt that that instrument was ‘stuffy’ in the trigger range. Whilst selection after personally playing several instruments for sale and excellent technique might be part of the ideal purchase process life doesn’t always work that way, and anyway it’s helpful to read the comments of others to narrow down what’s likely to work for you. Thinking about trombones 'speaking' well through the valve section and the variables to have in mind I came up with six - some of which will be more important that others – but there might well be others that should be on this list: bore size(s), valve size, f section wrap type, valve type, valve quality and qualities, and quality of the f section’s build. Reading generally the larger the bore and the larger the valve the better - so a 0.548” bore is preferred over 0.525” – but little if any data is available on rotor sizes. Simplistically air flow that has a 90 degree change of direction through the (rotary) valve (as on the standard Conn 88H) is better than 180 degrees (an on part of the YSL 448 ) however valve size and wrap type might well change the f section's overall air flow qualities. I believe that the Yamaha has a larger rotary valve (than is common on other makes) and that in part compensates for the greater angle and that the wrap type (with less tight bends) allows further benefit(s). The Rath 400 Bb/F (http://www.johnpacker.co.uk/Catalog...-BbF-R400-large-bore-8-12-Bell-Lacquer-102252) looks sensible to me – 90 degree turns through the valve, minimal and gentle bends in the wrap's pipe-work and not too much wrap overhang - but a second hand YSL 448 might be more affordable and work well enough for me. I wonder both what design features, etc. players should consider when buying a trombone to cover both Tenor and Bass parts, and what particular instruments other players have found that work well for covering that wide pitch range.