Most Folk/Roots/Blues fans would pony up plenty to see Carrie Rodriguez, Kelly Joe Phelps or Erin McKeown on their own. A triple bill for free with that line-up is a gift from the musical heavens. Here’s why:

• Rodriguez came to prominence over a decade ago when iconic singer/songwriter Chip Taylor saw her playing with the band Hayseed at South By Southwest and invited her to tour Europe with him, subsequently releasing five albums together. Her four solo albums have all been gems, and her 2010 EP with Romantica’s Ben Kyle, We Still Love Our Country, went Top 10 on the Americana Music Chart.

• Phelps spent a decade as a Jazz musician before converting to the Blues by way of Mississippi Fred McDowell and Robert Pete Williams. Phelps’ lauded debut, 1995’s Lead Me On, cemented the authenticity of his originals and his masterful translations of Blues classics, a quality that has been present on every one of his 10 releases over the past 17 years.

• McKeown is the wildest of wild cards, playing rootsy Rock, earthy Folk, sweet Pop and silky Jazz standards with equal passion and energy. She has toured the globe (with the Indigo Girls, Ani DiFranco, Josh Ritter, Andrew Bird and others) and released 10 solid and pathologically diverse albums, including last November’s F*ck That! Erin McKeown’s Anti-Holiday Album. Maybe we can coax her into a quick spin through “Santa is an Asshole” or “Visions I Have Had While High.