 During his career with Seether, Callahan received gold records for the bands successful work on the albums "Disclaimer", "Disclaimer II", "Karma and Effect", "The Punisher" movie soundtrack, the "" movie soundtrack, and has received a platinum award in Australia for the single, "Broken".Since quitting Seether, Callahan has spent time working with children in a Philadelphia music school called the Music Training Center.He has also played and toured with Metallica, Evanescence, Audioslave, Green Day, Staind, Breaking Benjamin, Slipknot, 3 Doors Down, Shinedown, Def Leppard, and Lionel Richie.