The Pop Bag

The Balloon Farm became much more than a discotheque, last weekend and the resident combo became much more than a pop-music ensemble

The occasion was the first New York appearance of The Mothers Of Invention, from deepest freakiest L.A. They are the perfect embodiment of all that is super-hyped about West Coast rock.

Forget that one Mother wears a sweatshirt which advertises "Folk you" in bright buttonese.

These eight musicians made the Balloon Farm a concert hall. They seized the stage and belted the world's first rock oratorio to an audience that was either too engrossed or too confused to do anything but sit and listen.

The show was a single extended number, broken into movements by patter, and fused by repeated melody themes. Especially notable was the use as leitmotif, of music from "Boris Godunov," sewn into the fabric of the song so that it became an integral part of the melody and not a sequin pasted on for class. On another evening – I have it by word of ear – the group lit into Stravinsky, with a rocking beat.

Te Mothers use the secondary technique of pop-parody with devastating effect. They goof brilliantly on the basso-falsetto hang-up of '50s teen music, and on the cocktail-clinking orchestration of the '40s. Their lyrics leave the Fugs gnawing scraps.

The whole show – call it a theatre piece and tell Beck and Malina to tail it back from Europe to catch this one – is surrounded by a pulsating lightscape. Oily color globs merge and counterpoint. It all flows freely, and for once, in sync with the music.

The Mothers of Invention haven't arrived yet, but they strive with outstretch. fingers toward something perceptively unique. Their first album, "Freak Out," is the most poorly produced package since the Hindenburg Zeppelin, but don't let this baby-dribble fool you. The

Mothers Of Invention are to be watched and leader Frank Zappa deserves your attention and your three bucks..