It's a wonderful performance, really capturing a Groucho sensibility. What helps is that he just doesn't do simply a good "impression," but a thorough acting job -- but far more than that, the performance includes improvisation which cuts at the heart of what we tend to think of Groucho Marx. Probably a third of the show is going into the audience and talking with people, or bringing them up on stage. The end result is that you don't come away with watch an actor do Groucho, but you've been taken back to -- as the title says -- an evening with the fellow.
It helps that Frank Ferrante has been performing as Grouch a very long time, before even the 25 years he's been doing this show. Right before he began doing An Evening with Groucho a quarter of a century ago, Ferrante starred in the play, Groucho: A Life in Revue, written by Groucho's son Arthur Marx, as well as Robert Fisher. That play is largely just Groucho, though includes a few other characters, and takes him from a young man starting out, all the way through his life to the weakened old man who still made appearances on TV and did some touring. I actually saw that show at the same Pasadena Playhouse, and it (and Ferrante) were terrific and memorable. What made the evening especially memorable for me, though, had nothing to do with the play -- seated in the row in front of me was George Fenneman, Groucho's sidekick/announcer from the old You Bet Your Life TV show. I admit to watch Fenneman for his reaction throughout the play. He loved it and, when it got to the enfeebled old Groucho, he was in tears. In fact, in Ferrante's end-of-show speech last night, he discussed the night that George Fenneman came backstage in tears and how Fenneman told him a story about his last time being with Groucho. (After the play, when Mark went back to talk with Ferrante, I came along and mentioned that about sitting behind Fenneman. He was amazed, and added, "See you again in 24 years.")
Also nice last night was that several members of the Marx family were in attendance, including one of his daughters, and granddaughter.
Because the play, Groucho: A Life in Revue, is quite a bit more complicated to do than this one-man show (well...two, counting the piano player), Ferrante years ago asked Arthur Mark for permission to do a one-man show in smaller venues. He got the permission, and An Evening with Groucho was born. Eventually, Arthur and the whole family simply gave Ferrante full permission to do the show with no restrictions. And so, here we are.
Hopefully the show will return to Los Angeles far sooner, though it might be playing near you wherever "you" may be in the country. (You can check the touring schedule here.) But in lieu of that, here's a little 7-minute documentary on the show with a great deal of footage giving you an idea of An Evening with Groucho.
(Side note, though you can seen him alone clearly a bit earlier, at the 5:14 mark you can see Sean Penn along with his then-wife Robin Wright-Penn in the audience, enjoying a bit when Ferrante clowns with a man in front of them.)