For jazz and blues fans, the best two shows are the ones where should a band blow chunks, the next one will probably redeem the night. Such power in numbers is the m.o. behind The Memorial Day Jazz and Blues Festivals held at Humphrey's Backstage Lounge. On May 29, it's the blues cats turn, with local cats Len Rainey, Billy Thompson, Billy Watson and others. The jazz day is even better on May 30, headed by trumpeter Gilbert Castellanos, who has combined with Sean Locier to form a quintet, and cool jazz guitarist Patrick Yandall. Over at Dizzy's, Seattle pianist Deems Tsutakawa flies down to join new San Diego flutist Bradley Leighton for a night of jazzblues and soul-funk on May 29. On May 28, it's jazz guitarist Sandro Albert, a new solo artist with a Brazilian edge who just recorded his new album with superstar vocalist Milton Nascimento, sax icon Kenny Garrett and Yellowjackets bassist, Jimmy Haslip.