Herbert, Friml and Romberg composed melodies that are always worth hearing. And who better to do them justice, one might think, than Jerry Hadley, who has made such a striking leading man not only in the opera house but, more relevantly, in EMI's Show Boat (11/88)? I have no doubt that many will be delighted with the results here. Yet these numbers come from an era of theatrical opulence and extravagance, and they surely make less than their full impact if not given full-blooded performances, complete with full period orchestrations. Here I find myself alienated by vocalizing that is altogether too mannered, and orchestrations that are often sketchy, fanciful and pretentious. A little goes a long way. The gimmickry extends on one occasion to combining the title song and ''One alone'' from The desert song, on another to mixing Friml's ''Song of the vagabonds'' with Romberg's ''Stouthearted men''. I really don't find that it works. Against the background of these accusations of gimmickry it may seem perverse to praise the use of Mario Lanza's voice in ''Golden days''. Yet Lanza at least gave unashamedly full-blooded performances, and Hadley and his orchestra are forced to follow suit. The difference shows.'