Synthesizers - call them ugly or beautiful - are a musical force in the '80s

If the word ''envelope'' means more to you than something you mail a letter in, if ''patch'' is not just a piece of a quilt and ''modular'' describes something besides your living room sofa - you're probably familiar with the musical electronic wonder of the age: the synthesizer.

Not long ago, the ''Synthesizer Explosion'' came to New York - a two-day seminar presented by Keyboard Magazine and New York University. Students, teachers, and anyone else interested were invited to learn about synthesizers as musical instruments, to hear them played (in concert, by Don Buchla and Jan Hammer), and to play them themselves.

The nub of this gathering was that the synthesizer can no longer be ignored, especially now that it's joining forces with the computer.

This is especially true in education, where it is increasingly important that teachers understand the technology of an instrument that promises to take its place alongside the trumpets, trombones, and snare drums in the band room. Says Dr. John Gilbert, director of the Electronic Music and Recording Studios at NYU, ''No music department can ignore it. The implications of it for music education are enormous.''

For a die-hard acoustic-piano player like me, with less than a kindergarten knowledge of electronics, the Synthesizer Explosion was a real eye- and especially ear-opener. Equipment trucks rolled up to New York University and roadies unloaded endless cases of the latest and best equipment. Rooms were set aside for demonstrations of new synthesizers, and one large hall was reserved for experimentation by the public. Anyone could stroll around the room, put on headphones, and fiddle around (as I did), or get serious on checking out a possible future purchase.

An illustrious panel of experts included synthesizer pioneer Vladimir Ussachevsky, Keyboard Magazine editor Tom Darter, and two men whose synthesizers carry their names: Robert A. Moog and Don Buchla. This panel gave talks on a number of topics concerning synthesizers.

Wendy Carlos, who turned ''Moog'' into a household word 1968 with her record of ''Switched-on Bach,'' proved in a talk and demonstration of digital synthesis that she is now happily ensconced in these newer and greener pastures. Her delight with the wonders of computerized synthesis was engaging, and the examples of her own music showed her to be a first-rate composer.

What main ideas emerged from this conference?

First, the importance of the human element in synthesis. Serious synthesists deplore the notion that they are mere technicians. They stressed creativity, stating that all the technology means nothing in the hands of an inept musician.

Then there was the issue of how to control the synthesizer. The keyboard has been the obvious choice, since it is familiar and not difficult to learn. But now some musicians favor using another instrument, such as guitar or trumpet, to control the synthesizer. Others suggested that the control need not resemble a conventional musical instrument at all.

The increasing popularity of synthesizers has raised questions and even protests. Some detractors insist that synthesizers rob musicians of jobs, with the substitution of one electronic instrument for any number of acoustic instruments. Others object on the grounds of the artificiality of the sounds produced by synthesizers and the fact they can never measure up to ''real'' instruments.

Supporters counter that the synthesizer is itself an instrument, not just an imitation of an acoustic instrument or instruments. They declare that there is no danger that any legitimate instrument will ever be replaced. They claim the sounds are not artificial at all to the acclimated ear. So the controversy goes on.

But the fact is that not only are synthesizers becoming increasingly popular, especially since they joined hands with computers, but they are being used more and more in commercial music where other instruments were used.

Consider how many sounds, musical and otherwise, that we hear on the radio, on TV, and in the movies which are produced by synthesizers. After all, why hire six horn players and a drummer when you can do it all with one synthesizer and a drum machine?

The experts agree that the '80s are the time of the synthesizer. Like any other musical instrument, the sounds it produces range from insignificant to highly artistic, depending largely on who's at the helm.