ANTHRAX guitarist Scott Ian was forced to miss the band's concert last night (Friday, April 12) at House of Blues in Lake Buena Vista, Florida after reportedly suffering from a bad bout of food poisoning. The show went ahead despite Scott's absence, with SHADOWS FALL guitarist Jon Donais — who has been touring with ANTHRAX since Rob Caggiano's departure in January — handling all guitar parts and the band performing as a four-piece.Fan-filmed video footage of the concert can be seen below. The "Metal Alliance Tour", which also features EXODUS, HIGH ON FIRE, MUNICIPAL WASTE and HOLY GRAIL, will stay on the road through late April. "Anthems", ANTHRAX's long-awaited, eight-track EP that pays tribute to the classic songs by some of the band's favorite acts from the 1970s, sold around 8,500 copies in the United States in its first week of release to debut at position No. 52 on The Billboard 200 chart. The CD was released in North America on March 19 (MRI/Megaforce), and on March 22 in Europe (Nuclear Blast). ANTHRAX's latest full-length album, "Worship Music", sold 28,000 copies in the United States in its first week of release to land at No. 12. The band's previous studio CD, 2003's "We've Come For You All", opened with just under 10,000 units to debut at No. 122.