Snapshots from Saturday and Sunday at the 37th Annual Sacramento Jazz Festival & Jubilee   Sam Rocha, string bass and tuba,  Blue Street Jazz Band  accompanies the group as they played gospel music Sunday morning.   Sacramento's MICK MARTIN and THE BLUES ROCKERS Mick Martin, vocals and harmonica Jimmy Pailer, guitar Kyle Roland (above and below)  Drummer Bruce Pressley tunes his drums as a fan blows cool air. Kyle Roland was discovered by Mick Martin at the Jubilee four years ago at the ripe old age of ten as he was playing along on his harp during one of Mick's shows. Mick heard him and had him come up on stage to play along and was taken aback not just at his ability to p