Another new session that was added to the music2work2 web site recently is 179. It is one of my new favorites. It is a mix of piano and strings. The first half is upbeat with a fast tempo, and it contains lots of "fancy finger-work. The second half is a much slower tempo, but variations of a predominant melody from the first part can still be heard.
At a length of 41 minutes, it is a perfect session "to work to."