Thanks for posting that. I wouldn't have seen it otherwise. Although Peter Filichia gives too much praise to Richard Greenberg for my taste, this next paragraph in his review captures my feelings anout Martha, Zip and why people should see it:
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Let’s not forget that as Gladys, we have Martha Plimpton, who excels as the woman that, in a smart Greenberg rewrite, Joey once Done Wrong. Plimpton rather resembles Elaine Stritch, who sang "Zip" in the famous 1952 revival, as Plimpton does here. Oh, it's once again shoehorned into the plot, but with more justification than ever before. If you’re a True Musical Theater Enthusiast, you’ll be more inclined to appreciate than criticize.