Ry Cooder and Leon Redbone. The usual reviews of Ry Cooder's concerts have differed mainly as to whether he is the best white blues guitarist or potentially the best white blues guitarist. If you like barroom-type songs done in a monotonous drone, you'll like Leon Redbone also. Saturday, April 27 at sanders Theater, 8.30 p.m., $3.50.

Jazz Notes. Sunday April 28 begins Boston Jazz Week, a salute to the city's jazz musicians plus a special tribute to Jaki Byard. I don't know if the following are all official events, but they seem to be good ways to join in the celebration:

Harvard University Jazz Band. The Jazz Band will offer a free concert including Chick Corea's "Spain" and Chuck Mangione's "Klee Impressions," featuring trombonists Carl Fontana and Phil Wilson. Arrangements by other top jazz bands are on the bill. Monday, April 29 at Sanders Theater, 8:15 p.m., free.

More Jazz. Clarinetist Bob Fritz brings his new group on Friday, April 26 to the School of Contemporary Music on Beacon St. in Brookline, 8:30 p.m.,$2...Reedman David Smith plays with the Music of the Spheres Orchestra Friday, April 26 at Stone Soup, 8:30 p.m.... The Boston Youth Jazz Ensemble headlines a concert of jazz musicians and groups on Sunday, April 28, at the B.U. School of Fine Arts Concert Hall, 8 p.m.

Folk Notes. Carolyn McDade and Nan Ackerman will perform old and new songs about women, Saturday, April 27 at the Arlington St.Church, 8 p.m., $2...Barbara Carns and a host of other performers will offer a concert of just about every strain of traditional American music Friday, April 26 at the Joy of Movement Center, 8 p.m., $2. Party afterwards.