The bell has rung and the class of '86 is filing in from recess. Here come a crew of record executives, talking bullishly of the coming pop-music season while they total up the profits from what's been a very good year. Straggling in after them, singly or in small groups, come some long-time truants, clutching new works that signify their intentions to go ahead and shoot for the moon. Stevie Wonder's got "In Square Circle" (Motown), his long-awaited new album, in the stores this week. Hall and Oates and a couple of old friends, the ex-Temptations Eddie Kendricks and David Ruffin, are clutching their joint class project, a soulful album recorded "Live at the Apollo," for release later this month on RCA.

Can that be Joni Mitchell with a new album, her first in almost five years? No title yet, you'll notice. Here come the New York bad boys, Richard Lloyd and Johnny Thunders, long rumored to be missing in in action. They each have new records, new bands, and some color in their cheeks, for a change. And filing in fashionably late are the two class favorites. The Queen of Pop, Tina Turner, trails a retinue of songwriters, record producers, musicians and accountants, all busy working on the follow-up to her universally adored "comeback" album, last year's "Private Dancer." Bruce Springsteen, Boss of the Schoolyard, has some brilliant songs about America, written out longhand in his notebook, intended, perhaps, for the album he'll be working on next year.

You can only get so far on a metaphor, but from here, this is the look of the coming pop season. Everyone in this class is a teacher as well as a student, of course. They're all looking healthy and thankful for past successes, and looking forward to a busy, competitive year. Despite their past earnings and potential for future growth, you won't find any arrogance here. Like good teachers and good students, the executives, stars, administrators and workers who make up the pop-music scene all seem willing to listen to and learn from each other, to explore new trends and try out new ideas. And that bodes well for the year

There was a time when record companies were slashing their staffs, when stars who used to sell millions of records found themselves selling a few thousand and playing for empty seats, and everyone associated with the pop-music business seemed to be singing the recesionary blues. That was in the early 1980's.

There'll be no more music industry bloodletting during the coming season. The biggest stars of 1985 - Bruce Springsteen, Tina Turner, Dire Straits, Prince, Madonna, Phil Collins, musically and racially a mixed and motley crew - each sold several million records, most from 5- to 10 million, a few considerably more. These are figures the major record labels can live with. Even the cleverer independent record labels are earning gold records, most featuring fresh-from-the-streets rap artists like Run-D.M.C., UTFO, and Whodini. For a time when corporate conglomerates still seem to be swallowing every smaller company in sight, these independent triumphs are a significant achievement - and a sign that the music industry as a whole is and should continue to be fundamentally healthy.

Another sign of that health is pop music's continuing fight against world hunger. During the coming year there will be more concerts, more recordings and more media events, all aimed at feeding the starving by mobilizing contributions from pop music's immense international audience. The Irish rock singer Bob Geldof launched the movement last Christmas when he put together a studio full of British pop stars to record a song he'd co-written with Midge Ure from Ultravox and Visage, "Do They Know It's Christmas?" The single, credited to Band Aid, became the biggest hit single in the history of British pop. Everyone from the stars to the technicians to the record distributors turned over all profits to Band Aid.

Galvanized by Band Aid's success, a group of American pop stars that included Harry Belafonte, Michael Jackson, Lionel Richie, Kenny Rogers and Quincy Jones set more all-time sales records with the all-star U.S.A. for Africa hit single, album and video cassette "We Are the World."

Pop music, with the help of television and satellite technology, reached the largest audience in its history earlier this summer when Bob Geldof and Band Aid put on the simultaneous Live Aid concerts in Philadelphia and London. It will be difficult for U.S.A. for Africa, Band Aid or any other organization to outshine the magnitude of "We Are the World," and especially of "Live Aid." But difficult or not, Band Aid and U.S.A. for Africa both intend to try to top their previous efforts during the coming year.

The sheer diversity of the significant artists about to deliver new albums will keep pop music as varied, and as unpredictable, as it was in 1985. We'll be getting everything from songs with a social conscience to sweet ballads, from charging guitar-rock to funky dance music.

Joni Mitchell's eagerly awaited new album is said to include highly politicized songs, aimed at real-life subjects and not pulling any punches. Bruce Springsteen's new songs, introduced one or two at a time during his recent tour, make probing observations about the state of the union. One, performed in Washington, D.C., is an unforgettable portrait of laid-off oil workers living in a tent city outside Houston. These will be among the raw materials for Mr. Springsteen's follow-up to the biggest album of his career, "Born in the U.S.A. " Meanwhile, Kenny Rogers's forthcoming album was produced by the Beatles' studio Svengali, George Martin. Barry Gibb, of Bee Gees fame, produced the next Diana Ross album.

A flowering of 60's-style rock, reinterpreted with a mid-80's point of view, will be among rock's most significant new trends this season. Every important 60 's idiom, from psychedelia to bubblegum rock, country-rock to folk-rock, is going to be examined, taken apart, combined with other elements, and played and recorded in garages, bars, clubs and concert halls throughout the United States and Europe, by big stars, professionals and unknowns. The 60's revivalism of 1985, spearheaded by hit albums like Prince's "Around the World in a Day" and Tom Petty and the Heartbreakers' "Southern Accents," was only the beginning.

The 60's readily come to mind when the existence of a "rock underground" is mentioned. But the phenomenon of do-it-yourself bands, recording for independent record labels, getting radio play mostly on college stations and performing in small dance venues, clubs and bars, is likely to produce some of the coming season's most riveting new music. This is a genuine underground, small-change compared to pop's biggest artists, but inventive, sincere, passionate and international in scope and sophistication. Among the bands to watch are Green on Red, Sonic Youth, Zeitgeist, Meat Puppets, Antietam, Miracle Legion, Husker Du, Long Ryders, Swans, True West, and two major-label standard-bearers, Jason and the Scorchers and R.E.M. When it comes to dance music, the Washington, D.C., Go-Go scene bears watching, especially leading bands like E.U. and Redds and the Boys.

Increasingly, the performers and bands who make it will do so with a multimedia marketing approach. More and more hits will be shaped, launched, made or broken by their accompanying videos. Video cassettes that document a full-length pop concert, or collect a series of individual videos, will be more and more competitive, battling it out with hit movies at the top of the charts that reflect video cassette sales and rentals. Pop music's visual adjuncts, along with upscale music formats like compact disks, all mean more money pouring into pop's coffers. The most bullish estimates of pop music sales for the coming season may turn out to be conservative.

MULTIFACETED JAZZ AND POP Mario Rivera, saxophonist, and the Salsa Refugees. Merengue-jazz. Sounds of Brazil, Sept.11. Milt Jackson, vibraphone, and Ray Brown, bass, leading a quartet. Mikell's, Sept. 13-14. Bill Frisell, electric guitar, with Tim Berne, saxophone. Roulette, Sept. 21. David Holland, bassist, leading a quintet. Sweet Basil, Sept. 24-29. Jimmy Witherspoon, blues and jazz singer. Sutton's, Sept 27-29. Dizzy Gillespie, trumpet, guest soloist with the Machito Orchestra. Salsa Meets Jazz, Village Gate, Sept. 30. Abdullah Ibrahim, South African pianist, leading his septet, Ekaya. Sweet Basil, Oct. 8-20; playing Duke Ellington compositions, Carnegie Recital Hall, April 18. Second Annual East Coast Asian-American Jazz Festival, with the violinist Jason Hwang and Glass Shadows, the pianist Jon Jang, the 16-piece East of the Sun Orchestra and many others. Jazz Center of New York, Oct. 25-27. Benny Carter, saxophonist-composer-arranger. Village Vanguard, Nov. 5-11; West End Cafe, Jan. 16-20. James Newton, flutist, in duet with David Murray. Greenwich Music House, Nov. 9; with a string quartet, Carnegie Recital Hall, March 19; "African Flower," an album of Duke Ellington pieces, October release on Blue Note Records. Little Jimmy Scott, jazz singer. West End Cafe, Nov. 27-30. Stevie Wonder has a new album, "In Square Circle" (Motown) in the stores this week. Sting, the singer-songwriter and actor, at Radio City Music Hall, Sept. 23-30. Hall and Oates share with David Ruffin and Eddie Kendricks a new album, "Live at the Apollo" (RCA), being released this month. John Thunders and Richard Lloyd, two founding father of New York's post-punk rock underground, reappear; the former at the Ritz Sept. 13; the latter, at Irving Plaza Sept. 14. Dire Straits, the guitar-rock group, at Radio City Music Hall, Oct. 1-3.