Our old drummer Ed would bring his 10 yr old along to rehearsals, he was a budding guitarist and would jam along with us on a couple of songs near the end, all good fun.

When Bass jr was a tot, I used to bring him along to rehearsal as I had no alternative childcare. On some (rough) recordings, you could hear his bouncer chair enthusiastically boinging away. On another, as the last note fades, he blew a long raspberry. I agreed on both counts; he was an excellent critic even before he could walk.