The consistent strength of Amy Rigby’s albums sometimes makes them just a bit difficult to write about — each of her albums is loaded with witty and telling songs about the occasional pleasures and frequent pitfalls of life as a single woman past 30 (or, these days, past 40), and her slightly rickety but powerful voice and smart, tuneful melodies make the perfect vehicle for her material. Rigby’s fourth album, Till the Wheels Fall Off, fits right in alongside her previous three sets, so what is there to say about this disc that hasn’t been said about the others? Well, just as important as the consistency of Rigby’s music is the fact she knows how to find any number of variations on her basic themes, and like the best singer/songwriters, she knows that each person can have any number of stories to tell, and she knows how to tell them with humor, clarity, and an emotional honesty that’s both affecting and disarming. That’s what made her first three albums so special, and makes Till the Wheels Fall Off just as impressive; much like John Prine, Richard Thompson, and Loudon Wainwright III, Rigby appears to be the sort of songwriter who has the gift of consistent excellence, and if that makes sorting out the value of one album over the other a tad difficult, it also means that they’re all rewarding listening. Anyone who ever smiled or cringed at the home truths of Rigby’s songs will get a laugh out of “Are We Ever Gonna Have Sex Again” and the title track, and have their heartstrings tugged by “Don’t Ever Change” and “Why Do I.” In short, Amy Rigby has made her fourth great album, and with any luck she won’t stop doing this anytime soon. – Mark Deming