. >> put the mike down and sang acapella. >> really?ent because the art is almost as great a passion as singing. >> yes. >> if i said you could only paint or sing for the rest of your life, which option would you take? you couldn't do both. >> i would have to do both because they're both very passionate for me but if my voice, because of my age, let's say, starts wavering, i don't want anybody to hear that. so then i would just retire to painting for the rest of my life. >> can you imagine not singing again? could you imagine the day coming where you retire? >> no. >> you don't think you'll ever give up? >> oh, no. i have to keep learning. >> danny, what do you think has been the secret of your father's success? if you were to try and crystallize it, what would you say? >> i mean, i think, again, it's, i'm doing a documentary called "the zen of tony bennett" and it is that focus and he's tremendously focused and calm. there's no entourage around him. he stays fit, stays healthy. he plays tennis, works out every day. >> you work out ever