The release of a freely-distributed Amiga program named Soundtracker by Karsten Obarski in 1987 started the era of MOD-format which made it easy for anyone to produce music based on digitized samples. Module files were made with programs called "trackers" after Obarski's Soundtracker. This MOD/tracker tradition continued with PC computers in the 1990s. Examples of Amiga games using digitized instrument samples include David Whittaker's soundtrack for "Shadow of the Beast", Chris Hülsbeck's soundtrack for "Turrican 2" and Matt Furniss's tunes for "Laser Squad". Richard Joseph also composed some theme songs featuring vocals and lyrics for games by Sensible Software most famous being "Cannon Fodder" (1993) with a song "War Has Never Been So Much Fun" and "Sensible World of Soccer" (1994) with a song "Goal Scoring Superstar Hero". These songs used long vocal samples.