One of the most commercially successful heavy-metal bands ever, Megadeth has maintained a solid career, including selling more than 20 million albums worldwide, and winning six consecutive platinum albums and seven consecutive Grammy nominations for best metal performance. The group is known for its distinctive guitar style, which involves complex arrangements and mewling ’n’ dueling guitar solos. On top of its numerous hits, the band is riding the success of its 2011 album, “Thirteen,” which debuted at No. 11 on the Billboard 200 chart. The album’s singles “Sudden Death” and “Public Enemy No. 1” both received Grammy nominations. Prepare to head bang heavily when Megadeth performs at the National on Wednesday, May 9, at 8 p.m. $35-$40. 612-1900.