Today is the 33rd birthday of David Ellefson, bassist and co-founder of thrash-metal pioneers Megadeth. Megadeth are best known for such thrash-metal classics as "Foreclosure Of A Dream," "99 Ways To Die" and "Peace Sells... But Who's Buying?" Ellefson himself is probably best known for the "Peace Sells... But Who's Buying?" bass line that plays at the end of the hourly MTV News updates. Born and raised in Minnesota, Ellefson

moved to L.A. to make it as a rock bassist. He formed Megadeth in 1983 with the man who lived in the apartment above him, guitarist Dave Mustaine. Mustaine was booted from fellow thrash rockers Metallica and used the angry energy that act produced to concentrate on playing a brand of metal that was faster and harder than anything that had come before it. He soon relinquished lead guitar duties to a series of sidemen and concentrated on being the band's vocalist and rhythm guitarist.

1985 brought the release of their major label debut, Killing Is My Business... and Business is Good. Its fast power chords and literate lyrics brought the group praise from critics who had never said nice things about metal before. 1986's Peace Sells... But Who's Buying? was also a hit with critics, and video play for the title track on MTV started to bring the fans around. The group toured tirelessly in support of the album and released the #28 charting So Far, So Good... So What? in 1988. Alcoholism and drug addiction dogged the band throughout its entire existence, but Mustaine finally cleaned up his act after a 1990 impaired driving conviction. As the group entered the '90s, they achieved their greatest successes. 1990's Rust In Peace hit #23, 1992's Countdown To Extinction hit #2 and 1994's Youthanasia debuted at #4. Megadeth, along with Metallica, is one of the few '80s metal bands to continue releasing albums and touring to great success. They released Cryptic Writings a few months ago and are embarking on a U.S. tour at the beginning of next month.

Other birthdays: Bob Crewe (Four Seasons), 66; Bryan Hyland, 54; John

Walker (Walker Brothers), 54; Booker T. Jones (Booker T. and the MGs), 53; Neil Young, 52; Arthur Tavares (Tavares), 51; Buck Dharma (Blue Oyster Cult), 50; Errol Brown (Hot Chocolate), 52; Donald Johnson (Taste of Honey), 49 and Leslie McKeown (Bay City Rollers), 42.