Accessible duo works with piano parts

[irrational]

Hi.

I would really like to learn some works playable with another player in preparation perhaps for a long future concerto work.
There are some great sonatas and other works, but I am not sure what would be a simple one to start with.
The instruments played by friends also limits what I would learn.

Does anyone have recommendations for pieces that are not too long (So can be a single movement as well) .
I'd say currently I am limited to: Double Bass (Advanced player), Guitar(intermediate classical) and voice(Advanced). Maybe piccolo/flute (Advanced).

I myself am between intermediate and Advanced I guess. Current works are Schubert Impromptu Op.90/3, Haydn Hob XVI:23 and Bach WTC1 - c-minor for instance.
Preferred era is Baroque/classical.