Tony Duggan wrote, re Previn:

>Also his Rachy Symphonic Dances.  The only version, in my experience, to
>leave the tam-tam reverberating on the last chord, as the composer asks -
>and very exciting it is also.

The score doesn't call for the reverberation - it only calls for a dotted
quarter note.  This is the way Ormandy and most conductors play it.
Personally, I prefer the shorter duration.  IMO if the tam- tam stroke is
allowed to reverberate, it dissapates all the considerable energy and
excitement Rachmaninoff has built up in this last movement.

Bruce