Metal Allegiance, the supergroup featuring Alex Skolnick (Testament), Mike Portnoy (Dream Theater), David Ellefson (ex-Megadeth), and Mark Menghi, will be celebrating their 10th anniversary at the Starland Ballroom in Sayreville, NJ on September 6. The concert will find the band joined by Troy Sanders (Mastodon), John Bush (Armored Saint), David Davison (Revocation), and more. Meanstreak…