hi !
thanks for the comment and the link!
I have now a new direct link to the tunes :

http://soundcloud.com/hyppolyte-bergamotte-jazz/tracks

the length of a jazz tune can vary with the feeling you do receive from the listeners.
When the jazz tune is delivered without listeners ,the length must be long enough to prove your sense on improvisation (on the given harmony),but short enough to avoid that listeners fall asleep !
:-))
Milou Pulinx