Dennis grew up in Syracuse, New York, and received his B.A. from Northwestern University in Evanston, Illinois.  He moved to the Twin Cities in 1992.

From 1992 until 1994, Dennis was employed at Hey City Stage, performing in the musical Forever Plaid.  Beginning in 1993, he became a full-time singer with the cover band Pizazz, a band he performed with until 2012.  He returned to the theatrical stage in 2004 when he performed in the musical revue Hot 'n' Cole at Ordway Center in St. Paul.  Dennis then appeared in My Way (Ordway Center), A Christmas Carole Petersen (Theater Latté Da), War of the Worlds: The Musical (Hometown Theatre), Mrs. Man of God (MMOG Productions), Orphan Train (History Theatre), Warm Beer Cold Women (Guthrie), and the staged reading of Little House on the Prairie (Guthrie), as well as appearing as a Holiday Singer in the lobby of Ordway Center during The Sound of Music (2007) and White Christmas (2008).  In 2013 he performed in Theater Latté Da's production of Steerage Song at the Lab Theater, and created and performed in Table Salt's Country Roads: Dennis Curley Sings the Music of John Denver.  The CD is available here.

His compositions include Love After Hours, Vampires! Horror!, U Betcha: The Making of a Minnesota Boy Band, Route 66: Cruisin' the American Dream, Whistling Past the Graveyard, Pride and Plot of Pointlessness, and Church Basement Ladies 2: A Second Helping.  His arrangements for Schoolhouse Rock Live! and Schoolhouse Rock Live Too! are published by MTI; the Love After Hours Original Cast CD is available here, as well as at the iTunes Store.

Dennis has served as Musical Director for local and national productions of The Marvelous Wonderettes, Schoolhouse Rock Live!, Rent, The Fantasticks, Here's Love,Power Balladz, U Betcha and Church Basement Ladies 2, among others.  He co-produced Pride and Plot of Pointlessness in 2006 and 2008, and Whistling Past the Graveyard in 2007 (for which he also served as stage director).