This year's "Day on the Green" concerts closed down over the weekend with Saturday and Sunday performances co-starring The Who and the Grateful Dead.

Balmy weather combined with the beautifully relaxed and friendly stage atmosphere to provide the 80,000 customers (two-day attendance) a memorable Indian Summer experience in the Oakland Coliseum Stadium.

The last time The Who and the Dead shared the same stage seems like a lifetime ago — that was on Sunday night, June 18, 1967, the last concert of the legendary Monterey Pops Festival. The middle of that show consisted of The Dead, The Who, and Jimi Hendrix.

Times and the music have changed since those flower-children days (it was, in fact, a couple of musical generations ago) and for both The Who and The Dead the years have seen considerable musical maturation. The Who no longer break up instruments to end a performance nor does singer Roger Daltrey wear a long robe; The Dead are no longer locked into a routinized set and their vocals and instrumental solos have long since become exciting and enjoyable.

The huge Coliseum crowds, however, did have some of the 1967 feeling; they were relaxed, anxious to enjoy the two internationally famed rock-oriented groups whose personnel have remained virtually intact for a decade, and they were eager to participate — clapping, swaying, cheering, digging the music and each other.

The Dead's long medley which included "St. Stephen," "Not Fade Away," "Help On the Way," "Slipknot" and a magnificent "Franklin's Tower" was about the best hour's live music I've heard from the group. At least I think so — after all these years the memory fades.

I can't recall Jerry Garcia's guitar being sharper in solo or on releases and Bob Weir's vocals (and also Donna Godchaux's) were blended marvelously into the instrumental sound. Keith Godchaux's crisp acoustic piano was fine in the outdoor atmosphere and, well, I just thought it was a hell of a good set . . . and I heard only two-and-a-half of the three-and-a-half Grateful Dead hours.

It is possible that the Dead are brighter and fresher these last few months because, as someone commented, "They're discovering themselves again" (after a couple of years in one or another form of splinter-groups).

And it is also possible that The Who, in contrast, playing much the same set for what seems like three years, could stand some refurbishing. Their Saturday performance certainly was better than last March's Winterland show, where everyone was out of sorts, but the excitement of spontaneity, of surprises on stage, was lacking for any who have followed the group regularly over the years.

Drummer Keith Moon played better than he has locally for a long while and John Entwistle's bass projected through the ensemble especially well. Daltrey's stalking and mike-tossing and Peter Townshend's stage-leaps were slick, as usual. Entwistle, aware of the hot sun blazing at the stage, strapped two bottles onto his mike stand and, through a straw, sipped the contents as the show progressed.

It is always rewarding to hear the "Tommy" production number, and "Summertime Blues" and "Behind Blue Eyes," and all the others, particularly with The Who in good physical shape.

The huge London and San Francisco stage set, with the wooded "music park" in the middle, was most impressive and the sound (by Showco out of Dallas) seemed excellent wherever I moved.

I wondered, however, why the baseball infield area was roped off and inaccessible to the crowd, now that the season is over. Does a young rock-concert audience really damage the soil and turf more than the cleats of the football Raiders?