Song Summoner: The Unsung Heroes comes out of nowhere to establish itself at the top of the small library of puzzle and casual iPod games. Pulling from the publisher's renown at crafting compelling RPGs, Song Summoner tunes into an inventive style of gameplay that revolves around the device's strength: music. It's an innovative game that showcases the iPod as a serious gaming platform.

When Ziggy's brother Zero is abducted by the Mechanical Militia, it falls to you to guide him through the rescue effort. While he's more than capable of fighting on his own, Ziggy needs the assistance of Tune Troopers summoned from music stored on your iPod.

As a conductor, he's able to transform tunes into units that can be directed in turn-based battles. Visiting the Hip-O-Drome allows you to distill tracks from your iPod into a variety characters. It's an innovative harmony between traditional tactical role-playing and music (and very different to other games that plunder your iPod library, like Phase and The Sims DJ).

Tough battles against the Mechanical Militia encourage you to build an advanced line of Tune Troopers. You do this by diversifying your army and raising individual ranks. Five distinct classes - soldier, knight, archer, monk, and mage - define a trooper's strengths, weaknesses, and abilities.

Mages, for instance, harness the power of magic, whereas archers can execute ranged physical attacks. As with any tactical role-playing game, success in battle depends on the strategic use of troopers. Taking a squad consisting entirely of soldiers into a battle against archers and mages that can wipe out your units at range is a losing proposition.

Even with the right units though, you need to bulk up on experience to increase trooper ranks. Defeated enemies reward you with Pitch Pearls for enhancing your units. Each trooper possesses a rank beginning with bronze. Spending Pitch Pearls allows you to raise a trooper's rank to silver, gold, and platinum.

Obviously, it's more expensive to upgrade to platinum than silver, but the payoff comes in greater attribute bonuses and new skills. Throw in the fact that troopers can only be used until their deployment points run out and you have a compelling, thought-provoking character development system.

Song Summoner takes these well-established tactical role-playing elements - character development and turn-based combat - and twists them into a unique gameplay experience by binding them to your music. The way in which the game leverages your tunes to create troopers is undeniably clever, but more so is the reward for listening to those songs outside of the game. Play Points earned for listening to music used in the game raises the corresponding units' morale and therefore increases their ability in battle. It's utterly brilliant because it causes you to engage the game even when you're not actively playing it.

When you are playing the game, you're likely to be enthralled by the amazing presentation. Square Enix once again pushes another platform to the bleeding edge with unparalleled visuals. Most DS games could only hope to look this fantastic. Considering how catchy the original score is as well, it's easy to see why Song Summoner is the best-looking and sounding iPod game. Period.

The game's only shortcoming comes from an overly-sensitive click wheel that makes navigating through in-game menus a headache. The radial menu used for commanding units in battle is particularly challenging. Even when accounting for this minor annoyance, though, Song Summoner sings of the iPod's ability to entertain innovative, high quality games.