The Martha’s Vineyard Regional High School was founded in 1955, making 1959 graduation year for the inaugural class. Half a century and countless diplomas later, the Class of 2009 readies itself to be the 50th class to fling their mortarboards in the air. In recognition of this, the Minnesingers annual spring show will be titled The Beat Goes On, and will feature a medley of tunes from the last five decades. After a recent performance at Jordan Hall at the New England Conservatory and a bronze medal win at the 2009 MICCA choral festival, the celebrated choral group returns home to the Island, under the direction of Jan Wightman, and choreographed by Lianna Loughman. Catch the show Saturday, May 9 at 8 p.m. or Sunday, May 10 at 4 p.m. in the high school performing arts center. Tickets are $10 at the door, with a Sunday Mother’s Day Special of $25 for a family of four. For details, call 508-693-5255.