Is there any more Klingon Opera?

Question

In 'Unification Pt II' in TNG, Worf walks into a bar and requests some Klingon Opera. It goes like this:

Now I quite liked what I heard in that scene and I was wondering Is there any other Klingon Opera that we hear in canon? If not in canon, non-canon sources are also accepted; I'm just dying to hear some more of it!

Answer 1

KlingonMusic.Net has a list of references to Klingon music in Star Trek episodes. The entries specifically identified as Klingon Opera, and which involved some on-screen representation (as opposed to characters just talking about it) are:

1. The example in your question:

‘aqtu’ mellota’ je – Klingon Opera, excerpt sung by Worf and Amarie in TNG: “Unification II” (“Aktuh and Maylota” in script; “Aktuh and Melota” in TKW)

2. A separate piece used in two Deep Space Nine episodes:

“BOOOOW-cha-daaay” – a duet from a Klingon Opera (referred to as a “Klingon La Boheme” in the script) that Worf sings (and acts) along with in the Defiant during DS9: “Looking For par’Mach in All the Wrong Places;” a shorter excerpt from the same opera is heard in the episode of DS9: “In The Cards” while Nog is filtering out subharmonic frequencies in Worf’s Klingon Opera collection.

Other entries from the list which were actually sung in episodes are just Klingon "songs" rather than opera per se, but they may also be of interest.