What a tremendous week for jazz in Boston--especially jazz piano.

For instance, take tonight. Stanley Cowell, one of the finest jazz planists to come into the picture in a long time, opens up for a four-day engagment in the Jazz Workshop. He's not alone. He's got the Health Brothers, Jimmy on tenor and Percy on bass, and Billy Higgins on drums to round the rhythm section out.

Cowell is probably both the most innovative and unheralded planist to come into Boston in years, but it is more than likely that the Heath brothers will steal all the glory.

However, Cowell knows how to make his presence felt even with the finest and loudest of colleagues. On his most recent album, Brilliant Circle, Cowell not only overshadows some tremendous artists, but proves that a good planist can still coordinate a band if he wants to.

Cowell's work on Handscapes and Handscapes II with the Piano Choral is even more exemplary of the sweeping, authoritative style of this still youthful musician.

Shows begin at 9 and 11 p.m. and 1 a.m. at the Workshop at 733 Boylston St.

Friday night at 8 p.m. pianist Oscar Peterson moves into Symphony Hall with guitarist Joe Pass. Neither is really coming out of moth balls, but the tickets still aren't a bargain. If classic jazz piano interests you (Cecil Taylor fans may be turned off by Peterson's stuff) then the $5 and up ticket prices won't affect you.

McCoy Tyner finishes off a strong week with a six-day outing at the Jazz Workshop beginning Sunday. Tyner is another brillant planist who has gone far past the days when he played second to John Coltrane. This mostly romantic player will bring his usual stable of excellent back-up musicians and some new numbers to the Workshop.