These are the ones I have found that have already been posted at Mudcat. I will be adding more to this thread.

Country Boy Down in New Orleans (Snooks Eaglin)

Do You Know What It Means to Miss New Orleans? (from Louis Armstrong)

Down in New Orleans (Memphis Minnie)

Little Old Town Called New Orleans (Jerry Jeff Walker)

Mardi Gras in New Orleans (Henry R Bird a.k.a. Professor Longhair)

New Orleans Is Sinking (Tragically Hip)

Sadie Green, the Vamp of New Orleans

Take Me Back to New Orleans (Chris Barber)

The Battle of New Orleans (written by Jimmy Driftwood, recorded by Johnny Horton)

The City of New Orleans (written by Steve Goodman, recorded by Arlo Guthrie et al.)

Way Down Yonder in New Orleans

Witch Queen of New Orleans (from Redbone)