Fads come and go. Sounds change. One minute it’s synthesizers; then it’s vocoders. One thing stays the same, though: A good songwriter with a great voice always satisfies. That’s why Portland-based Roy Davis and his band The Dregs — Justin Maxwell, Kerry Ryan and Travis Kline (not pictured) — are building such a fan base ‘round these parts. Davis’ artfully ragged voice illustrates songs about life, love and all the things in between, bringing to mind voices like Bruce Springsteen, Ryan Adams and Jeff Tweedy. It’s a little alarming to discover that Davis is just 22 years old, and already has two albums under his belt — “Grey Town” and 2008’s “Deadweight,” an album that has received play on AAA stations across the Northeast. Roy Davis & The Dregs will bring Maine-bred Americana to the Unity Centre for the Performing Arts at 7:30 p.m. Saturday, Dec. 20. Tickets are $7, and they play with the Waldo County folk-rock powerhouse Tree By Leaf. For more, visit www.roydavismusic.com.