loop do … end runs the block indefinitely until Stop is pressed. Loops are black holes for program flow: code placed after a loop block is never reached. This means multiple bare loops cannot coexist in one run — threads or live_loops are required for concurrent loops. Sonic Pi raises a safety error if a loop runs without a sleep, preventing CPU lockup.

Examples

loop do play rrand(50, 90) sleep 0.5 end

Code here is unreachable

Assessment

Explain why two consecutive loop blocks in a buffer means only the first is ever heard. Rewrite using in_thread to run both simultaneously.