A piece that normally only has a few notes for tuba is Dvorak New World Symphony. The reasons for this have been debated by tuba players ever since. Did the tuba player in orchestra that gave premier upset Dvorak, or was the few notes in slow movement added later as the composer missed the richness of the tuba there - but never got around to adding tuba to rest of symphony, not even in the finale? I think it is the latter.
Robert Ryker has arranged full part for tuba as it might have been if Dvorak had conceived the symphony with tuba in the first place. Here is link to download the part