Bay seniors who long to have their minds blown as in days of yore are encouraged to trek out to the Great Wall of Oakland at Broadway and West Grand this Saturday night. From 8:30 to 9:30 Bandaloop, the gravity defying dance troupe with be flying around like a rock climbing ballet company. It’s free but bring a mat or beach chair for geezer comfort. Bandaloop has been around for 20 years and you’ll be asking yourself why it took you so long so catch up with them. I certainly am.