Boston is NOT Boston without Brad Delp.Styx is less Styx without Dennis DeYoung. I saw Boston at Comiskey Park in Chicago in 1978 opening for Steve Miller and The Eagles. They were very good. They pretty much pulled off the stuff from the albums although I could swear there were some things that were added electronically. Who cared, we were all buzzed anywho. But when you lose one of the two most identified members of a band...it would be like the Stones going on tour without Keith.
Good luck with all that.