Aging Rockers' Last Resort: Undress Fest

Turtle Lake Music Fest '95 Today through Sunday Turtle Lake Resort, Union City, Mich.

$125 for all three days (800) 480-7004 Expect a full moon when Eric Burdon sings "House of the Rising Sun"this weekend. The erstwhile Animal is booked into the Turtle LakeMusic Fest '95 in Union City, Mich.

It's a clothing-optional resort.

Burdon joins rockin' reptiles Blue Oyster Cult, Kansas and AlanParsons in the three-day event that begins tonight. (They're missingthe obvious booking, ex-Turtles Flo and Eddie.)

The Classic Rock All Star Band kicks off the fest at 4 p.m.today. This threadbare outfit brings together drummer Pete Riverafrom Rare Earth; Jerry …