The sort of person who finds a new interest and goes into it with unquenchable passion, she appears to have no braking mechanism. So when her group, vintage string band music specialists the Carolina Chocolate Drops took a hiatus this autumn, what did she do? She teamed up with the Drops' cellist, former New Orleans street busker Leyla McCalla, and set off on the tour that brings them to Glasgow this weekend.
In just a short conversation down the line from their first UK stop in London, Giddens effuses about the African-American theatre music of the early 1900s and her passion for Gaelic waulking songs.
She also tells of her discovery of the banjo's origins as a black musician's instrument, the jigs she found that black fiddlers used to play and a whole lot more that she and McCalla condense into a concert that mixes extensive social history research with a love of communicating a good tune and songs that mean something.
"It sounds complex, what we do, and there is a lot to it, I suppose," she says. "We have gone into what makes African-American music, where it comes from, the whole Haitian, Creole, Southern States melting pot, and how it goes together. But it is really simple. In the end we just play and sing and try to convey what it is about this music that we love so much."
Performing on stage was never part of Giddens' plan. At home in Greensboro, North Carolina, the family listened to her father's Peter, Paul & Mary and other folk revival albums, as well as the many different types of music that her mother latched on to. They would sing together but singing was not something Giddens thought about as a career. She was going to be an artist until, in her final year of high school, she attended a choral camp.
"I had been on choral courses before and never thought too much about it," she says. "But this one was fun and suddenly I thought, 'Hey, people who sing opera do this for a living and sing all the time - I wanna do that."
So without knowing much about opera and unable to read a note of music, she applied to Oberlin Conservatory in Ohio. She passed the audition, she surmises, because she had a good ear and was able to pick things up really fast, and once she was there she threw herself into the music department wholeheartedly.
When she was not studying music theory or rehearsing, she was working in the office, sending out press releases about department activities and writing articles for the college magazine.
"I loved opera and I still do one symphony concert a year," she says. "But the constant round of auditioning did not appeal - I just wanted to sing - and being a Jane Austen fan and thinking that the folk dancing I had seen advertised was the English folk dances they did in Austen's books, I had become side-tracked."
Back home in Greensboro with a job in graphic design, she threw herself into the local folk dancing scene and decided she wanted to play dance music. So she bought a fiddle, took a few lessons to learn the basics, and followed that with a banjo, on which she is more or less self-taught from books and records.
Her studies at Oberlin served her well because she could sight-read the books of old tunes, such as Kerr's Merrie Melodies, that friends put her way.
Having first played in a Celtic folk band, she next got together with singer and multi-instrumentalist Dom Flemons and formed Sankofa Strings, the forerunner of Carolina Chocolate Drops. With the help of their mentor, Joe Thompson, a then 90-year-old fiddler, they dug deeply into 1920s and 1930s string band music.
Giddens has since explored the music of the 1850s and 1870s and learned Gaelic songs from a friend back home who took Celtic Studies at Edinburgh University.
"I am fascinated by how the Gaels interacted with Native Americans and African slaves when they came over to America from Scotland and how their music fed into the American tradition," she says.
"I could go on all day about it but, ultimately, the best way of illustrating how all these different cultures became intertwined is to sing the evidence."
Rhiannon Giddens and Leyla McCalla play Oran Mor, Glasgow, on Saturday.