Traffic is the biggest brass band on the streets. In between swelling swooshes of many mediums, vehicles of every key sing onomatopoeic songs―car horn honks, backup truck beeps, klaxon awoogas, train choos, and bicycle bell brrngs―all day and all night and all afternoon, fading in and fading out, with timbres thrown back to the Jazz Era, when everything was a-beepin’ and a-boppin’ with syncopated stop-sign rests, and Doppler shift decays like the slide of a trombone on the very last ictus, into the howling road rhythms ahead.

The classic horn of popular automobiles (what you would call a honk as opposed to a beep) is tuned between a Major and Minor Third Interval. The oft-played double beat is like that of a Morse Code “A” (dit, dah (· —)), and was probably copied from railroad engineer beats. It can be notated as below: quaver, crotchet rest, crotchet, quaver rest, crotchet rest, assuming we’re in 4/4 time.

