Park Street Station, the meeting point of the Red and Green lines of the MBTA and gateway to the Common, has always held a special place in my affections. the squeals and groans that the trains and trolleys make, the intermingling smells of apples, pizza, carnations, and urine, the mobs of people at rush hour, have somehow always created an exciting atmosphere that appeals to me.

It was therefore with some dismay that I returned to Boston this fall to find that the MBTA bosses have ruined Park Street station. It wasn't that they remodeled it into one of those sterile, tiled waiting stops like one finds at Copley or Prudential. Nor did they trim it in gaudy patriotism, as they did at Government Center. And they didn't close down the fruit and flower stand. Instead, over the summer months, the MBTA has prostituted the character of the old Park Street complex by injecting one of the most pernicious elements of 20th Century Americana -- Muzak.

I have an immense phobia about Muzak. It all goes back to 1971 when I was stranded in the Albany, N.Y., airport for nine hours. At that time I was nearly driven mad by the insidious burblings that followed me around the airport. I tried frantically to escape them. I fled into the coffee shop. They followed me. I darted into the bar. They followed me there too. They even trailed me into the rest rooms. Since that time, whenever cheerful and inane melodies seep out of wall speakers, I look uneasily over my shoulder.

And so, when I returned this fall and innocently descended into the Park Street station, I was horrified to find that one of the last refuges from Muzak had been stolen away from me.

Park Street's brand of Muzak is not that bad. Not bad, that is, when compared to the Star Market, or the airport. The MBTA has selected a soundtrack that mingles old-time supermarket melodies with contemporary garbage rock and roll -- the bubble gum music that dominates AM radio. It's a curious combination.

Last Tuesday night, braving the advances of pickpockets and Boston Common groupies and avoiding an MBTA security guard who I'm sure wanted to nab me for loitering or dope dealing, I attended a two-hour Muzak "concert" at Park Street.

The show led off with "On Saturday Morning," the theme from The Sterile Cuckoo.

The number didn't alter any of my prejudices. It was basic Muzak -- a cheerful scampering over the "Saturday Morning" melody with a saccharine string and brass ensemble. It wasn't a great performance, but it was spiced up (and immeasureably improved) by the periodic squeals filtering down from the trolley stop on the upper level. These interruptions punctuated the melody pretty well, salvaging an otherwise sorry performance.

Each number is followed by a computerized 15-second pause before the warbling revives like an audio-phoenix every time you think (hope) it has died out. The next notable contribution to the show was a harmless burble version of "I Want to Make It With You."

After a couple of inane digressions into the Forties came the highlight of the show -- "Take a Letter to Maria." Taken from AM radio teeny bop, the Muzak version of this 1971 pop best-seller was actually an improvement on the original. Of course, that's not saying a great deal, but the Muzak arrangement created a surprisingly tolerable piece.

"Take a Letter to Maria" was the only song in the concert that elicited a noticeable response from the Park Street train-waiters. A fat old wino leaning against the wall, waiting for the Ashmont train, swayed blissfully with the melody in oblivious appreciation, without opening his eyes or loosening the grip on his paper-bagged Gallo.

Following that up was a spirited "Midnight in Moscow," easily the second best number on the program. Loud, brassy and energetic, the Muzak rendition of this old instrumental number was nearly as impressive as "Take a Letter to Maria." Both came close to not sounding like Muzak at all -- a high compliment indeed.

The performance -- as Muzak performances go -- was pretty good. But all too often, the concert degenerated into a rehash of old airport delights which undermined the newer and more interesting numbers. The MBTA has put together a good collection at Park Street, but it can never be more than that.

The most consistent strength of the show is the periodic arrival of the trains and trolleys, which bring back, for a brief moment, the familiar roars, bells and squeals.

The upper and lower levels at Park Street present the same tunes in different settings. Downstairs, the speakers are subtle and the Muzak low-keyed. Upstairs, because of the openness and noise, the Muzak is piped over bullhorn speakers at a louder volume. The result is a nasal blaring sound, like something that would come out of the PA system at a Nixon rally. The upper level is a better place to listen -- if only because the trolleys are better equipped to drown out the melody. But when they are absent, the high-decible Muzak is nearly unbearable.

As if all this weren't a bad enough violation of the abrasive Park Street atmosphere which many of us loved, every twenty minutes the theme song of the MBTA comes on, sung in sweet cherubic voices: "The T can take you where you're going, Take the T to where you've never been..." This is really too much to endure. Crass American is in poor taste, but commercial propaganda is an unpardonable transgression.