It'a realistic to say that Joseph Arthur was not likely on many people's "most anticipated acts at ACL" lists. Arthur, a versatile songwriter in the middle of his career, is neither a hotshot buzz act nor a headliner-caliber name. And if that sounds like an unkind way to begin a review, well, it's hard to imagine that Arthur himself would argue with that assessment of his role in the contemporary rock landscape. In the world of Kanye West, Coldplay and Stevie Wonder, a guy like Arthur is a middleweight.

But to a surprisingly robust crowd on Sunday afternoon, he was also a diamond in the rough. Playing unaccompanied, Arthur filled the stage with an electric guitar and his own voice (and a couple of canvases for painting), serving up the evocative sort of zag-where-you-thought-they-might-zig songwriting that he's built his career on.

Those sort of songs, conveniently, are also the kind that Austin audiences tend to have a fairly endless appetite for, which might explain why a somewhat obscure songwriter from Ohio could hold his own in a Sunday slot at ACL. On the set's second song, "Honey and the Moon," Arthur rolled off a bridge that featured an extended spoken-word sequence that erred on just the right side of awkward-white-guy-rapping, before ending it with a robust guitar solo—a fine introduction to a crowd that didn't seem to know him.

But any performance is about more than just how the artist fits into the culture of the festival. Yeah, maybe we come for Arcade Fire or Cee Lo, but a festival like ACL is also where we learn about artists who've escaped our notice, where a guy like Arthur gets a chance to hold the same stage as a rising star like Hayes Carll or a legend like Wanda Jackson. And when it came to proving himself worthy of that opportunity, Arthur acquitted himself nicely. He excels at creating an intimate connection with an audience, no mean feat on the Austin Ventures stage, and his performance had the warmth of a Waterloo in-store. He strapped on a harmonica, looping his electric guitar to free up his hands, even taking to hanging canvases with spray paint to create some on-the-fly art. In short, Arthur was comfortable and relaxed, just right for the late afternoon in Austin on a Sunday.

An artist like Joseph Arthur spends a hard-fought career proving that he's worth booking at a festival like Austin City Limits. When he played on Sunday, he proved that he deserved it.