QUOTE(Yorkie @ Jun 7 2008, 09:21 PM)

I have got it down as the tenor Trombone,Brass family as a non transposing instrument but not too sure
I would not give full marks for that answer, unless you had the actual melody in front of you, as not all tenor trombones have the lowest four notes on the 'cello; nor does the three-valve tenor tuba. Plug tenors (i.e. the ones with a thumb valve) and four-valve tenor tubas do cover the range completely. Also, the tenor trombone sometimes, and the tenor tuba always, play from Bb transposing (treble clef) parts in the brass band. Similar complexities apply to the bass clarinet, which is built in a number of varieties. The standard military band instrument in Bb has written E (concert D above the 'cello's low C) as its lowest note; because of Wagner's use of bass clarinet in A, all orchestral bass clarinets have Eb; and many are now made with D and C as their lowest notes, so these would also cover most 'cello tunes.
The orchestral horn in F covers the 'cello range downward and would also cover most 'cello tunes upward. Which of the two instruments has the higher note depends upon their players, but I can believe that 'cello tunes exist that even good professional horn players would find impossible.