Wrap around is a setting which specifies the highest notes which can be played in a style track. When the chords detected on the arranger goes beyond this point, they will be transposed to an octave lower.
This is used to maintain notes within the natural range of the instrument selected for the track. Notes played too high will sound unnatural. So this setting ensures that the natural range is maintained for the track.
Wrap around is not applicable to the drum tracks. For the other tracks the default value is 9. Change it to a better position based on the sound selected for the track. It is recommended to keep different values for different tracks so that all the tracks will not be transposed together to a lower octave.