1
general::
1. Moving to a rhythm or conforming to the movements of others, as in The kids marched in step to the music. [Late 1800s] 2. in step with. In conformity or harmony with, as in He was in step with the times. The antonym to both usages is out of step, as in They're out of step with the music, or His views are out of step with the board's. [Late 1800s] Also see IN PHASE; OUT OF PHASE.
American Heritage Idioms
2
general::
Phrase(s): in step (with something) [and] in time (with something)
Fig. keeping in cadence with music. • John, your violin isn’t in step with the beat. Sit up straight and try it again. • I’m trying to play in time., Phrase(s): *in step (with someone)
Fig. [marching or dancing] in cadence with another person. (*Typically: be ~; get [into] ~; march ~; keep ~.) • Please keep in step with Jane. • You two, back there. You aren’t in step., Phrase(s): in step (with someone or something)
Fig. as up-to-date as someone or something. • Bob is not in step with the times. • We try to keep in step with the fashion of the day.
McGrawhill's American Idioms And Phrasal Verbs