in_unison
1. [ adverb ] speaking or singing at the same time; simultaneously
Synonyms: in_chorus
Examples:

"they shouted `Yes!' in unison" "they responded in chorus to the teacher's questions"

2. [ adverb ] in complete agreement
Synonyms: in_accord
Examples:

"my feelings about the matter are in unison with yours"

3. [ adverb ] at the same pitch
Examples:

"they sang in unison"

Similar spelling:   inning
  innings