The quintet playing Pennies From Heaven, according to Songbook, is comprised of Lester Young on tenor saxophone, Bill Harris on trombone, Hank Jones on piano, Ray Brown on bass and Buddy Rich on drums. The high quality of the video because it is taken from a film, Norman Granz at Montreux Jazz: Improvisation.
A straight bio of Young, who was known as Prez, is posed at PBS. A look at his style can be found at NPR. Here is an excerpt of the NPR piece, which was written by Tom Vitale:
Sweetness is what Young was all about. When he started to gain attention, the dominant style of the day was the aggressive, hard-driving saxophone of Coleman Hawkins. But Young played in the upper range of his tenor in a lyrical, relaxed style.
It is a nice feature, and here is another. Here is Goodbye Pork Pie Hat. The latter was written in honor of Young by bassist Charlie Mingus, who is among the performers in the clip. It was later renamed Theme for Lester Young, according to Wikipedia. Young traditionally wore a pork pie hat.