When Pete Townshend wrote “My Generation” in 1965, with its adolescent yelp of a lyric, “Hope I die before I get old,” he never imagined that 17 years later, his band, the Who, would continue to keep on keeping on. Now, after nearly two decades of enormous success, there is a question as to how much longer the Who will continue to operate.

The current show, which stops at the Silverdome Thursday evening, has been described as their “final” American tour. As the band members all edge toward the age of 40, the grind of a rock tour becomes less and less attractive. Guitarist Townshend: “I am still very confused about what I should be doing, even in terms of the Who’s career. We’ve sat around and we’ve decided that we don’t want to go on forever — even seeing an end to the band’s career in 18 months, at least in live performing.”

THE WHO’S initial success coincided with the rise of “swinging London,” in the mid-1960s. Two Townshend compositions “I Can’t Explain” and “My Generation,” quickly stamped the band as a major force in rock and roll. By the time the group traveled to America, in 1966, only the Beatles and Stones outranked them in the rock and roll pantheon.

That same year, the group released the “Happy Jack” LP which was notable for the inclusion of the first extended song cycle, or mini-opera, in rock, “A Quick One While He’s Away.” Three years later, Townshend further extended the form for his magnum opus, “Tommy.”

His second double-album-length rock opera, “Quadrophenia,” was released in 1973.

After Quadrophenia, the group seemed to reach stasis. During the five years preceding Moon’s death in 1978, the group released just two albums, “Who By Numbers” and “Who Are You,” neither of which equalled their earlier sterling efforts.

Thus, when Moon died it was widely assumed that the Who would pack it in. But instead of quitting, Kenney Jones was enlisted to play drums and last year the group put out “Face Dances,” a perfectly adequate recording, but lacking the fire and spirit of their best work.

Early this summer Townshend released another solo album, his fourth, “All the Best Cowboys Have Chinese Eyes.” In the last year both Entwhistle and Daltrey also completed extra Who recordings. Despite all of these outside projects, the Who did find time to record a new album, “It’s Hard,” which has just been released. It includes nine Townshend originals and a trio of tracks from Entwhistle.

MOST SIGNIFICANTLY, the Who have decided to tour again. It’s their first series of American dates since 1980 and, as mentioned earlier, possibly their last.

Says Townshend: “There was so much animosity around the band (last year): a lot of us are still at odds about what we want to do. And I don’t think what I want to do as a musician or as a performer has really got anything to do with the Who at all.”

The Who will perform at the Pontiac Silverdome Sept. 30. Also appearing are the Clash and Eddie Money. Showtime is 7:30 p.m. Tickets for the concert are $15 and are available from all CTC outlets.