Isn't there only one original Beach Boy still alive? That could explain having a "backup artist" play their instruments. ;-)
there be: brian w, mike love and al jardine (who dennis w described as “a man waiting for a bus”
There is one Wilson brother alive, Dennis and Carl are deceased.
Mike Love is an original member along with Brian Wilson. The other band members have been there a long time (and away a long time).
Glenn Campbell took over for Brian Wilson when he stopped touring in the mid-60s and also played on the albums. He is not involved in this tour as he is going through his own retirement tour with his kids.