Just like guitarists and keyboardists, you and the keyboard player need to switch registers when you find you're in the same range. If the keyboardist is super low, you go to the middle of the neck for those sweet mid-bass notes until he goes up again, then you can go back to the deep bass notes.
Talk to the keyboardist beforehand to arrange for him/her to play higher more with the left hand to give you room to breathe; this is common courtesy and I've had a good relationship with keyboardists who know this and are even greatful to me for freeing them from having to play in the low register while I'm around.
Talk to the keyboardist beforehand to arrange for him/her to play higher more with the left hand to give you room to breathe; this is common courtesy and I've had a good relationship with keyboardists who know this and are even greatful to me for freeing them from having to play in the low register while I'm around.