Yes I do play tunes and sing songs, differently each time.
I guess that Northumbrian pipe variations,although written down,are intended to be played with a little more freedom,than a classical musician might treat them,my natural instinct is to take variations and then try and work something new from them[When I can] ,but I would hesitate to call myself a Jazz Musician.
Richard Bridge raises an interesting point about the ensemble nature of a good session,the need to cut down twiddles,so that the overall sound gels and the importance of listening to one anothers music.
In traditional jazz instruments take turn at solos,and then come together for ensemble playing,a session does not give the same oppurtunity for individual solos.
over ornamentation in a session can lead to musical cacophony,it is necessary[i.m o] for participants in a session to recognise the importance of the overall sound above individual virtuosity.
Dick Miles
Miles