David Crosby is ensconced with a very elite group of musicians who used their songs and harmonies to end a war, discrimination and government wrongdoing. Bob Dylan and Joan Baez are others in this small group of troubadours that made a difference in the 1960's and 70's.
Whenever performers -- such as Mary Bridget Davies in A Night With Janis Joplin, at the Lyceum -- impersonate iconic figures, they're going to be compared to the original, whether they like it or not. They certainly can't be surprised when they are.
For social gatherings at home built around screening movies, outstanding rock documentaries and concert films are virtually guaranteed crowd pleasers, particularly if your home theater set-up includes a quality sound system.