Hi Bernard.
In BiaB, a Push plays the chord either an 1/8 or a 1/6th note earlier than the beat.

From the Help:
Add Pushes to Chords
Pushes in Styles
Styles can push any instrument so that the instrument plays before the chord begins. This is very common in Jazz and other Pop music, and gives the music a more natural sound.

"Pushes" (sometimes called anticipations) are chords that are played before the beat. For example, in Jazz Swing the piano player often pushes a chord change by playing the chord an eighth note before the beat.

To use keystrokes:
Type the caret symbol ‘^’ before the chord. (The caret symbol is located above the 6 on the keyboard.)
Type a single caret to get a chord an eighth note before the beat.
e.g. ^C7
Type a double caret to get a chord a sixteenth note before the beat.
e.g. ^^C7

Hope this assists.

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