This is a brand-new arrangement (published TODAY)! I've been planning it for a while and now had some time to get it done. It's a bouncy set of gavottes from Bach's Orchestral Suite No. 3. Available now from Cimarron Music:

Bach: Two Gavottes arranged by David Werden for Euphonium and Piano

Here is a video of the two pieces, as they are written in my arrangement. Note that the recap of Gavotte 1 could make a nice, short encore (it starts at 1:53 on the recording).