This is the first full-on musical in the Scoobyverse.
The plot treats Bram Stoker's book Dracula as an account of something that really happened, rather than a novel, if Vincent Van Helsing is a descendant of Abraham Van Helsing from the book.
This movie was included in Cartoon Network's Scooby-Doo! Back to School Marathon (August 10-11, 2013).
A few descriptions of the film use the name Scooby Doo: Song of the Vampire, which might have been its working title.