the.com/sequencer

means A device or program that records and plays back a series of musical notes or control signals in a precise, programmable order.

from Built from 'sequence' — Latin 'sequentia', from 'sequi', meaning 'to follow.' Things that sequence are simply things that make one event follow another, in strict order. The musical sense emerged in the 20th century alongside electronic instruments and early drum machines, where engineers needed a word for circuits that stepped through a fixed series of notes or triggers — the 'follower' logic of Latin repurposed for synthesizers and step sequencers.