According to info I found here (https://www.jazzdisco.org/savoy-records/discography-1931-1944/session-index/), A1, A2, A4 to A7 were recorded by the Lester Young Sextet on April 18th, 1944. A3 and B1 were recorded by the Lester Young Quintet on May 1st, 1944. B2 to B6 were recorded by Johnny Guarnieri Swing Men on April 18th, 1944. B7and B8 were recorded by Earle Warren And His Orchestra on April 18th, 1944. Everything recorded in NYC.