imperialbari wrote:...Exactly the Bartok concerto would be the reason for the F contra version. In general I would consider the Eb contrabass being a better choice...
It is a bit confusing to distinguish between the bass and contrabass trombone. Nowadays the F bass is very seldom used, Eb not at all. Maybe because there are no modern instruments made?! One exception is the bass sackbut in F or Eb. But those sackbuts are only used for period performances. The thing tuned in F commonly used today is the contrabass trombone, which in turn is a minimized Bb contrabass (Miraphone and Thein makes modern Bb contras even though they are hard to play). An F contra has approximately the same dimensions except for the lenght that a contra in Bb has and instead uses a dual valve system to be able to play chromatically down the cellar. There are a few F contras with long slides with handle for all seven positions though. It also has a different voice from the F bass which in turn is closer in size to the tenors. For example Brahms symphonies sounds very well on modern alto in Eb, tenor in Bb and bass in F. The 5th of Beethoven would be a fine candidate for alto in F maybe.
Yamaha did make a modern F bass for Douglas Yeo. The instrument can be seen, if you scroll down a bit on the page, on this link
http://www.yeodoug.com/articles/trombon ... llery.html. You will notice that the instrument is not at all that massive as an F contra.
Contras in F an Bb can be heard en masse for example on the sountrack of the movie Planet of the apes...
To conclude, a light plastic bass trbn in F in a nice color could be both useful and fun.
I'd also feel much better playing it in bars instead of my expensive Kanstul contrabass...