The posted clip was analyzed by Elizabeth Zarkov of The Charismatic Voice, who's a degreed professional opera singer and vocal coach. She mostly focuses on Ann's vocals, but does give Nancy her props for the amazing intro. As a a former guitar player myself no, it's not terribly technical, but it's very well done regardless. I love the early work from Heart and I'm a fan of both Ann and Nancy, but they haven't stayed relevant in later years. I think we can safely say Nancy is one of the greatest women guitarists. For virtuoso guitar work check out Molly Tuttle.