MacLennan's original song, "Fallin' Deeper",[3] is featured in the Twentieth Century Fox film Marley & Me: The Puppy Years (2011) soundtrack.

[7] MacLennan began his professional music career at 16 completing session work for Grammy Award-winning mixer Tom Weir.

[5] MacLennan earned a bachelor's degree in Ethnomusicology from University of California, Los Angeles (UCLA) with emphasis in jazz guitar in 2010.

His mentors include: Carl Verheyen, Tim Pierce, Kenny Burrell, Jimmy Wyble, Tamir Hendelman, Ron Anthony and Wolf Marshall,[8] the author of Hal Leonard's Wolf Marshall Guitar Method and Power Studies.

[6] The iBook is divided into three sections, "Major", "Minor" and "Dominant"[14] musical phrasing with genre specific core-elements, rather than formal scales and drilled exercises.