The CW's DC Comics-based TV universe is growing yet again, with "Legends of Tomorrow" joining "Arrow" and "The Flash" on the network. CBS is also getting in on the DC action, with "Supergirl" taking flight there in October. And all four superhero shows share more than just DC Comics source material and Executive Producer Greg Berlanti. They each have composer Blake Neely creating iconic themes and scores for each series and its heroic (and villainous) characters.

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Neely joined CBR TV's Kevin Mahadeo on the world famous CBR Yacht at Comic-Con International in San Diego to talk about the surprising growth of the "Arrow" universe and how he approaches shifting tones and each news series. He also talks about finding balance between each interconnected CW series and what it's like being compared to John Williams any time you do work with the Superman family of characters. Plus, if given the opportunity, he already knows what he'd do with Batman and Aquaman.

In the first half of the conversation, Neely explains just what "iconic" means when it comes to themes, and how he approaches that when superheroes are involved. He also speaks to the darkness of "Arrow," the light of "The Flash," and how the two series being intertwined allowed him to find some common ground with the music. He then talks about what fans can expect from "Legends of Tomorrow," which brings characters from each show as well as new ones into a new situation.

On how much he thought about the darkness of the character and tone of "Arrow":

Blake Neely: From the beginning, Greg Berlanti said to me, I want this to be dark. We're not gonna do a happy super hero. Think Batman, think Darkness." So I read the script and went away and wrote some things. None of us had any idea this would grow into such a universe. It was sort of the first time DC was getting into television, in a way, since the '70s. Well, I guess there was "Smallville." But it's really interesting that that has now grown into all these characters coming to TV, but each one needs their own thing and their own... so every time you sort of feel like starting over.

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On finding the right balance for "Flash" to ensure it fits in the same universe as "Arrow":

For me, what I benefitted from, was introducing Flash within an episode of "Arrow." It had to be different, because he was a very different character, even when Barry Allen walks in that episode, he's light and bubbly and you think, "Oh, this is different." But it also couldn't be so different that it couldn't fit in the "Arrow" universe, so there was a lot of what he would become, what the show would become, but it needed to -- it had to be in a style that could hold hands with "Arrow," because they did tell me -- though I ask them not to tell me much -- they did tell me we're gonna have a crossover episode, these characters will intermingle, hopefully we build a bigger Justice League-type universe. So I tried to write in a style that was similar but gave him his own thing, because Arrow has no superpowers, Barry has all superpowers.

5:00 - On whether he took a new approach for "Legends of Tomorrow," with characters from both shows as well as new ones:

On using different instruments with familiar themes to make each show still exist in its own version of the world:

The cool thing about music is you can use a theme, but in a different instrumentation, and it's still the theme so it still reminds you. If I chose to do "Legends of Tomorrow" with all heavy metal guitars, and Barry's Flash theme is more string orchestral, I could just have it played on guitars and suddenly it sounds like he entered the "Legends of Tomorrow" universe. That's a really fun trick we have. So like I can do a cover version of Flash's theme with my "Legends of Tomorrow" band.

In part two, the focus shifts to one of Neely's other new shows this fall, CBS' "Supergirl." The composer talks about trying to create something as memorable and iconic as John Williams' "Superman" theme, creating something unique, and where the show fits tonally with regard to his CW series. He also discusses what potential themes for Batman and Aquaman would sound like, including how Aquaman should have a certain amount of "swagger."

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On standing in the shadow of John Williams' "Superman" theme when working on CBS' "Supergirl":

I've was asked a couple days ago what was the hardest theme I've written so far, and it was "Supergirl." You have such a canon of -- I mean, you've just got John Williams' theme, first of all, but -- it's such an iconic -- you know, when people think of comics they think of Superman and the S, everything. You know, you're told basically, 'write something that's that cool,' that's that memorable. I don't know if it's gonna be memorable. So that took a while and a lot of tries, a lot of stabs, a lot of "What if we try this style? What if we try that style?" And what we ultimately ended up on was doing a traditional orchestral score with a nod to the Williams-[Richard] Donner films and it just kind of works on the character. She's related to Superman, so why not have our score related to John's?

On where "Supergirl" fits tonally with other Superman family adaptations as well as his other work:

I would say tone-wise it's not like "Man of Steel." It's toned more like the Christopher Reeve "Superman" where it's fun. The villain's an over the top villain, but he's fun. She's having fun with learning her powers and learning to fly again -- she suppressed her powers for twenty years or something. I would say if "Arrow's" dark and "Flash" is lighter, then "Supergirl" is just fun.