MANDATORY screen tests for musicians before they are ever allowed to play a note in auditions? An end to concert tours and live appearances? Round-the-clock "video radio" on dozens of cable and pay television programs?

All these and more will come to pass in the '80s, according to many video and music analysts. Last year, sales of videocassette recorders (VCRs) hit a record three million units, up 60 percent over 1979. In March, RCA will introduce SelectaVision, its videodisc reply to the Pioneer and Magnavox laserdisc systems. Cable and pay-TV programs are multiplying fast. And all of these systems will be hungering for material.

So the music-makers are ready to cash in on a burgeoning home-entertainment industry that by 1990 is expected to reach into three out of four American homes now using color television. (The evidence of that explosion will be on view at the Washington Hi-Fi and Stereo Show in Rosslyn next weekend).

Sensing a chance to recoup the financial losses of the last year or so, the record industry has plunged into the audio/visual waters headfirst. Almost all the major companies and many recording studios have created extensive video departments. Musicians Leon Russell, Todd Rundgren and Michael Nesmith have opened multi-million dollar video studios.

Of course, the medium is still in an embryonic state. Jo Bergmann, Warner Bros.' director of television and video services warns that "it's too early to judge things by the home market since there's not enough machines," but is confident that "there will be a lot of changes in how music reaches the public."

Some recent examples: With limited airplay and no live appearances, but with a vivid, exciting video clip to support it on dozens of syndicated videorock television outlets, David Bowie's "Ashes to Ashes" became his first No. 1 single in eight years.

Melissa Manchester recently taped a special concert for Home Box Office showing this month; when it's shown again later in the year, it will be released as both a videodisc and videocassette, the first such direct marketing tie-in. HBO and other pay and cable stations regularly use video clips to fill gaps between programs.

An executive for EMI/American has suggested that it might be sensible to "screen test" new acts in the future with an eye to their video potential. In their contracts with record companies, many groups now demand a specific alternative: Give us tour support or give us video.

The Keefco company has produced over 400 video projects, including such artists as Toto, Hall and Oates, Journey, Forienger and The Knack. Producer John Weaver of Keefco says his company has suddenly been bombarded with questions, mostly from musicians who are concerned about their video futures: "We couldn't exist if the musicians weren't paranoid about how they look on television."

Blondie's dreary "Eat to the Beat" (which reportedly cost $140,000 and was delayed a year in anticipation of the coming of videodiscs) is probably the most successful pop-music videocassette on the market (10,000 copies), but the group had already released a follow-up album before it came out in that configuration.

Despite a growing consumer market, most rock-video products are still used for promotion. There are a number of syndicated shows on television programmed entirely arund promotional video material provided by record companies. Chrysalis' Linda Carhart is currently providing 26 programs with clips of her label's artists. Particularly in the last year, she says, programs such as "Hollywood Heartbeat," "The Pop Show," "Radio Picture Show," "Backstage Pass," "Video Jukebox" and "Video Concert Hall" are giving us an avenue where we have a group that radio won't touch. And the promotional expense is similar to, and is really an extension of, advertising expenses.

Clips have helped establish acts such as Gary Numan, the Boomtown Rats and Devo; provided a showcase for many new bands; and sustained the careers of other bands that seldom tour. Paul Simon, Linda Ronstadt, Paul McCartney, Diana Ross, Joni Mitchell and Fleetwood Mac have all produced and been deeply involved in concert videos. And now jazz and classical music are beginning to figure heavily in the increasing activity.

If the market proves a success, "people will buy videodiscs and videocassettes like they buy a T-shirt or program, a souvenir. It's clear that video is going to play an important role in the merchandising of music," says Seth Willenson of Selecta Vision.

In general, videocassettes and videodiscs ("videos" as they are called in the industry) fall into two catagories: The familiar performance/concert tape; and the conceptual/story-line form, in which the musicians act out the themes or story-lines of the songs, oten on elaborate sets. To go beyond concert footage costs money, and many record companies are reluctant to make that commitment in the face of an industry-wide downtrend. Many executives are skeptical about whether videos can bear repeated viewings. (Although, of course, the video can be shut off while the audio continues to be enjoyed.)

Conceptualizing "lets you do something radically different from a live performance," says Paul Flattery of Gower, Fields and Flattery. "But I'm not even sure it's going to be a big thing because it's so hard to do really good video." Flattery, who is leading a new British invasion in the video industry, did Bowie's "Ashes to Ashes," which won a top award at the MIDEM international music industry festival in France last week. He also put together the Kinks' "One for the Road" cassette and worked on the "Eat to the Beat" project."But too many of the record companies expect high creativity with fewer dollars," Flattery says.

More than 4,000 new albums were released last year, but only a tiny fraction of that market will convert to the new technology during the next few years. Aside from the financial drawbacks, many artists will find it extremely difficult to adapt to the exactness of video. It's one thing to illustrate a single song -- but the artistic failure of "Eat to the Beat" proves just how difficult it is to sustain momentum at album length. Some of the songs are inspired, some are horrendous. On the other hand, rock operas could make a comeback. Marty Balin of Jefferson Starship wrote "Rock Justice" specifically for video; unfortunately it was a disaster. Artists like Harry Chapin, whose songs are musical short stories anyway, may benefit greatly from video emphasis.

The advent of video may also provide many bands with a reasonable alternative to touring, often an aggravating and money-losing proposition for all but the biggest bands. For the audience, it offers an alternative to expensive tickets, parking and crowded arenas -- and a replayable alternative at that.

Many industry insiders also see video as an end-around to the increasing restraints of radio, feeling that video and cable in particular can sustain each other in the same way that records and radio have. They also feel that cable exposure will enhance ancillary income for cassette/discs in the future.

But the dangers are equally evident. Will record companies only invest in video for superstar acts with proven sales potential? Until the video software market gets more bullish, they'll find it hard to justify production costs with such a small potential return. Can video overcome the basic drawbacks of visual pop music that have relegated it to late-night status on television?

Will video augment musical texts, or will it take the emphasis off the music? How will artists who have worked concert crowds adapt to the intimate setting of video? Will the music industry mimic television and film's passion for pretty faces even more than it has already?

Says Chuck Stadler, who is best known for his Devo films and has also worked with Elvis Costello, Madness, Graham Parker and Nick Lowe, "if a group already has a visual to present, they will serve as a link between image and dialogue."

For the future, it makes little difference which of the currently incompatible videocassette or videodisc systems survive; they'll all need a video base. The proliferation of cable will create a huge market of its own. The advent of big screens and stereo television sound will have an impact here also. One of the nagging problems for video right now is that it's basically a monaural medium; until 1982, SelectaVision will be mono, as are all of the videocassettes. Some industry observers forsee a time when round-the-clock cable music programs will offer the same variety as flipping the radio dial does now; they also forsee simulcasts over television and radio, a King Biscuit Hour of the airways.

Although all the record companies seem to accept the inevitability of video, they are sending out mixed signals as to their level of commitment. Warner Bros. has produced 52 video pieces, at a cost of from $1,500 to $20,000 per song, all of which have gone for promotion; the recently released Rod Stewart concert videocassette, which sells for $40, reportedly cost $75,000. Concert packaging will definitely be the most common format during the initial stages of video expansion, yet many of the groups will undoubtedly experiment on their own, or with partial record company funding.

David Hadue, editor of Video Review magazine, hopes that artists will understand their limitations in a new medium and delegate responsibility to experienced video-filmmakers. Adds one video producer, "it's a pie everybody wants a slice of. But people are going to have to make gut decisions until the industry settles down."