Here is a solo rendition of a movement from Elgar's 'Serenade for Strings'..
It is the Larghetto of the work, which is full of mystery, and timeless song like tone. It also allows you to use the really low notes on Anglo concertina, on the left side keyboard, at the beginning, which is very melodious. [contrasting with the higher notes, later on].
https://www.youtube.com/watch?v=qrpH6JuK5aw