Acme 534 low pitch triple tone train whistleIntroducing the Acme 534 low pitch triple tone train whistle The Acme locomotive whistle has 3 pipes which have been tuned roughly to a Dm triad (F5, A5, D6) and polished by hand. Being tuned in this was helps it to mimic the whistle on an old American steam train. Each low pitch is generated by a metal organ pipe with a durable plastic mouthpiece. Also known as the Locomotive Whistle which originated, so the story goes, on the Leicester and