While professional musicmakers boggle, the U.S. public is quietly turning an unpromising record into a major pop hit. Oh, Happy Day, written by a lanky (6 ft. 1 in.), 17-year-old Cleveland high-school junior named Don Howard (full name: Donald Howard Kaplow), is a rudimentary little piece. To the accompaniment of his own guitar, Donnie himself moos his happy tune with the hoarse lilt of a fogbound ferry whistle. Sample chorus:
The moon is shinin',
Oh happy night,
Come to me, darlin'
And hold me, oh, so tight . . .
The melody has a folklike...