WHEN VAN MORRISON composed and wrote Astral Weeks, he lived over on Green Street, between here and Central Square. The album was a transition. Van Morrison had been called "moody, unpredictable, perverse, often downright willful," as Them's lead singer. His first solo album, Blowin' Your Mind, included a song called "T.B. Sheets," eight or nine minutes of guttural rantings--the archetypal early Van Morrison song, embodying everything anybody'd ever called him, and all the while intensely creative. Astral Weeks moved away from all that, not so much in Van's writing, for the words still come from his troubled days in Belfast, as in its music--loose and light, reminiscent of cool jazz.

When Van sang "Astral Weeks" last Friday at the Orpheum, it wasn't the same. It was tighter, more solid, like the music he's made since the album Astral Weeks. At one point during his performance of "Cypress Avenue," the strongest song on that album and the one closest to his work on Blowin' Your Mind, he said, "I don't wanna tell you about all of that Belfast pain and suffering." With that statement he summed up his music after Moondance: a more joyous, tighter, harder rock music, like his early music, but much more secure lyrically. There have been two solid albums since Moondance, His Band and the Street Choir and Tupelo Honey, and Van Morrison has become immensely popular. He came to the Orpheum on the crest of another change. He moved to California from Woodstock, New York, made a home in Marin County, and documented the change on Tupelo Honey. The most consistent aspect of Van and his music is his ability and willingness to change both.

IN CONCERT he retains some of the old ranting. "He Ain't Give You None," from Blowing' Your Mind, was his most powerful effort of the evening: Scat singing over his choir, improvising, creating tension, and finally letting the band blow. It was the only time all night his band--tight, disciplined and nameless--could display its talent. He also sang "Cypress Avenue," and revealed his own essential contradiction. There is a showman within Van Morrison, and the tension between that showman and an apparent detachment creates his stage presence. His band gave him a soul-style introduction, thirty seconds of sustained chording, and on he came--to sing "I've Been Workin'," without his guitar, just alone at the microphone. His detachment was extraordinary. By the time he sang "Cypress Avenue," however, he'd worked himself into a pacing tension that led to high kicks, head shaking, a shouted "Too late to stop now," a dropped microphone, and then he'd gone. The theatrics were unexpected, and that much more effective.

Morrison began to use his voice non-verbally, as an instrument. In most songs he would bring the band down to a groove and then simply scat sing over that groove. "Caravan" had a beautifully timed and syncopated, "doo-doot" scat chorus from the choir, and "Tupelo Honey" had a long scat singing section. The scat singing is an undercurrent, a constant reminder of the building tensions in Morrison's music.

It is also a reminder of the jazz influences present in his music. Just as Astral Weeks was centered around a cool jazz feel, there are still jazz elements in Morrison's later music. "Moondance" has always been a jazz song. The live version has an intimacy, a lightness characteristic of cool jazz, of nightclub music, that the smoke-filled cavernness of the Orpheum couldn't destroy. But for my six bucks, the best song of the night was a perfectly rendered fifties version of Erroll Garner's "Misty." Slightly electrified, the song was a magnificent example of transplanted, uptempo, fifties nightclub jazz. The bass line walked brilliantly and the piano fills and the piano solo could've come from the late show at Birdland. And Van's gourd, subtle vocal would have made King Cote proud.

VAN MORRISON also makes some of the best dancing music this side of the Four Tops. Both "Domino" and "Wild Night" were big hits on AM radio, and he performed both onstage with as much spirit as he had on record. "Domine" is one of the best of the nonsense lyrics songs. Listen to it, it makes absolutely no sense. But you can dance to it, and imagine it coming over your car radio. Transplant the whole image to the Orpheum Theatre, with the bassman dancing frantically by himself just offstage, and you have a picture of Morrison's new music. "Wild Night" has more meaning, but is just as joyous and just as much fun to listen to. These two songs summarize the new Van Morrison: uptempo and very much alive.

A word here on the band. Van Morrison has always had trouble with bands; it's a function of his temperament. He broke up his band right after Tupelo Honey, fired his manager, and then let Warner Brothers browbeat him about a tour--to capitalize on his popularity, presumably--while he collected himself and a new band. This band, its members unfortunately anonymous, is as good a group of musicians as Van has ever had to play behind him. They blew tight rock when they had to and, more difficult, knew precisely how to play softly, and to hold the chords for Van's scatting. The choir, one-third of which was Van's wife, Janet, sang gospel backgrounds nicely all evening.

Peter Wolf introduced Van as "the Belfast Cowboy and his band." An accurate description of an emigrated Irishman now living in Marin County. Van Morrison makes music that is heavily influenced by the indigenously American music of black people. Yet, it's synthesized into an intensely personal music with its own statement. Since Moondance, that statement has been joyous. Van Morrison makes music that's fun to listen to; comes straight to your heart like a cannonball.