High Marks for Upcoming Festival Acts : Jazz: From the performers at contemporary-oriented Long Beach event to the mainstream-leaning Pasadena shows, there are no rotten apples in the lineups.

It’s hot, it’s muggy, it’s summertime. Want some musical relief? Try the midsummer jazz festivals: Long Beach Jazz, in its sixth year, will take place Aug. 13-15 at Rainbow Lagoon in Long Beach, and the third annual Pasadena Jazz Festival is set for Saturday and Sunday at the Ambassador Auditorium in Pasadena.

To give an idea of who’s who and what’s up, here’s a tip sheet on the artists who’ll be performing at these events. We’re assigning letter grades from A to C+ (there are no rotten apples in this barrel of jazz stars).

In Long Beach, the contemporary side of jazz is being accented. The lineup for the opening show, Friday at 7 p.m., shapes up like this:

* Randy Crawford: Would this pop-based singer be included in the jazz ranks if it weren’t for her vocalizing on the Crusader’s smash hit “Street Life?” in the late ‘70s? Probably not. C+.

* Stanley Turrentine: Listen to the tenorman’s recent “More Than a Mood” CD and you hear a veteran at the top of his game. A-.

* Gil Scott-Heron: The singer-pianist’s politically pointed selections always seem to have a contemporary currency. B+.

Here’s the roster for the Saturday concert, which starts at 2 p.m.:

* Chaka Khan: This gutsy, eclectic singer has lots of energy and, for someone who usually resides in the world of R&B;, demonstrates a pretty good feel for jazz material. B+.

* Freddie Hubbard: When this trumpet player is in the mood to really go for it, there simply is not a better jazz artist anywhere. A.

* The Yellowjackets: The foursome-- Russell Ferrante on keyboards, Jimmy Haslip on bass, Bob Minzter on sax and Will Kennedy on drums--takes jazz/fusion to new creative levels. B+.

* Patrice Rushen, Jeff Lorber and Ndugu Chancler: The two keyboard players and the snappy drummer work mostly in the pop-jazz-R&B; arena. All have excellent musical sensibilities. B.

* The Birdland Allstars with Ernie Andrews, Lorez Alexandria, Teddy Edwards, Art Hillery and others: These veteran performers from L.A. could turn out gritty, blues-based mainstream performances in their sleep. A-.

* Barbara Morrison: A blues shouter of the highest order and a balladeer as well, she is nothing short of captivating. A.

The show for Sunday, also at 2 p.m., stacks up like this:

* Lou Rawls: Rawls can swing and he can belt the blues, but most of his material leans toward unctuous pop swill. B-.

* Poncho Sanchez: The conga drummer, who leads a superlative crew, makes no bones about his affection for driving, energetic numbers in the salsa and be-bop-tinged-with-Latin veins. A-.

* Hugh Masakela: The South African trumpeter plays pretty but he has never demonstrated a sophisticated jazz feel. B-.

* Wayne Henderson’s Next Crusade: The ex-Crusader trombonist, abetted by current Crusader saxman Wilton Felder, investigates tunes that fall mostly in the deep-funk arena that characterized his former band. B.

* Roy Ayers: You have to hand it to this vibist--he can make anything from R&B-rooted; stuff to ardent be-bop come vibrantly alive. A-.

* Fattburger: This unit from San Diego plays pleasant, not particularly original funk jazz. B-.

* Al Williams’ Jazz Society: The drummer’s band, featuring saxman Charles Owens and trumpeter Nolan Smith, plays no-holds-barred hard bop. A-.

Overall rating: B+. Tickets, $25 to $125, are available by calling (714) 740-2000 or (213) 480-3232. Information: (310) 436-7794.

The Pasadena event leans more toward the mainstream. Here’s the lineup for Saturday’s 8:45 p.m. show, “Brazil Spectacular”:

* Dori Caymmi: The singer-songwriter-guitarist concocts seductive pieces, their lone drawback being their resemblance to one another. B+.

* Ivan Lins: Incredibly gifted, Lins is arguably the king of contemporary Brazilian songwriters, responsible for such classics as “Velas.” A-.

* Ricardo Silveira: The guitarist’s steely sound is magnetic but his jazz-rock approach to Brazilian vehicles doesn’t always wear well. B.

Sunday 2 p.m. show looks like this:

* Diane Schuur: The svelte singer sometimes stomps her foot on the gas and zooms into overkill, but she is capable of telling, swinging versions of standards and originals. B+.

* The Clayton-Hamilton Jazz Orchestra: John Clayton’s arrangements, the succulently musical drumming of Jeff Hamilton and a crew of L.A.’s best jazzmen makes this band, which accents the blues, a definite smile-maker. A.

And here’s the roster for Sunday 6 p.m. concert:

* Dave and Don Grusin: The siblings sway back and forth between light contemporary fare and equally pleasant, though hardly earthshaking, mainstream numbers. B-.

* Ken Peplowski: The clarinetist-tenorman delivers swing-to-be-bop persuasively. B+.

Overall rating: B+. Two free concerts will take place Sunday outside on the auditorium mall: harmonica player-vibraphonist Hendrik Meurkens at 4:30 p.m., and the zealous post-hard-bop of Black/Note at 7 p.m. Information: (800) 266-2378.