Finally, we get to the bottom of this Zatanna/Zatara business!
The Story: "Murder by Melody!" by Gerry Conway, Dick Dillin, and Frank McLaughlin. The JLA reconvenes after letting Allegro escape, and Zatanna suggests that sorcery is behind his abilities.
She says that his music weakens the barrier between her and her mother, so if she can get his mysterious machine, it can possibly solve two problems at once!
Allegro, meanwhile, starts to play his mad music in an abandoned concert hall, which he then broadcasts all over the Earth!
As you can see, it has the same effect on kids that KISS' music did in the 70s.
The JLA finds an ancient text that Zatanna believes Allegro learned his magic from, which she thinks has driven him mad.
They then find Allegro and Black Canary, via a spell from Zatanna, uses her Canary Cry to dispel the demons, which gives the other heroes a chance to knock Allegro out and get his Mad Synthesizer of Death.
They then turn to Zatara, who tells the story of how he met and fell in love with Zatanna's mother, Sindella.
They use Allegro's machine to open the portal to another dimension. Here they meet a sorcerer named Highlord, who has Sindella as his prisoner! He tells the heroes Sindella is dying, and when she does die, her daughter will take her place! To be continued!
Roll Call: Superman, Batman, Wonder Woman, Flash, Green Lantern, Green Arrow, Black Canary, Elongated Man, Red Tornado, Hawkgirl, Zatanna
Notable Moments: I like how the Allegro story ends half-way through the issue. There might have been a temptation to pad the story to fill two full issues, but its kinda neat how the JLA goes from one story to the other.