If you haven’t heard of the cheerfully named supergroup Mr. Sun, you’ve certainly heard its proponents, four of the finest musicians on the American roots scene: renowned fiddler Darol Anger, guitarist Grant Gordy, Scottish bassist Aidan O’Donnell, and mandolinist Joe Walsh. Mr. Sun has seized upon the inspiration of Duke Ellington’s brilliant, sly, & urbane re-interpretation of Tchaikovsky’s Suite as an opportunity to salute and re-invent this wildly multi-faceted work anew through the lens of the American String Band, a musical form which contains myriad styles and is presently engaged in a marathon upheaval of innovation and expansion.