The keyboard does not let you adjust accompaniment volume while you are in the Record mode. You need to set the volume to the desired level prior to recording by doing the following steps:
1. Press SONG MEMORY until Play appears.
2. Press the ACCOMP VOLUME button.
3. Adjust accompaniment volume to desired level.
4. Press SONG MEMORY until Record appears.
5. Begin recording.
This applies to WK-3000, WK-3100, WK-3200, WK-3300, WK-3500, WK-3700, WK-3800, and WK-8000