Jam Bruce Jam is the sweet, innocent drummer of Mystery and probably the most sheltered of the four. He's an enormous KISS fan and genuinely dreams of being a musician, but his strict religious mother strongly disapproves of rock music. Because of her influence, Jam has grown up considerably more sheltered than his friends. He has curly/wavy dark hair, a rounder youthful face, and a softer appearance than the other boys. His normal clothes are typical teenage '70s clothes, but he sometimes ends up dressed in the conservative outfits his mother chooses for him. His friends love teasing him about the contrast between his mother's idea of a respectable young man and the rock musician he wants to become. Jam is earnest, excitable, awkward, loyal and good-natured. He's less confident than Hawk and less shameless than Trip, but he's not completely passive. When his dream or his friends are threatened, he can surprise everyone by standing up for himself.

Hawk Hawk is the cool, outspoken frontman of the group and the lead singer of Mystery. He's got the most obvious rock-star confidence, constantly making sarcastic remarks, talking trash, and trying to act tougher and cooler than he really feels. He's quick with a joke and isn't afraid to stand up for himself or his friends. At the same time, there's a nervous, insecure side underneath his attitude—particularly when he's performing or dealing with girls. Hawk has long, shaggy dark hair, a slim build, youthful features, and a scruffy late-'70s rocker appearance. His wardrobe is heavily influenced by hard rock: worn T-shirts, jeans, boots, denim/leather jackets, and KISS-related clothing. He looks like someone who spends most of his free time hanging around record stores and practicing with his band. He's passionate, competitive, stubborn and loyal. He wants to be taken seriously as a musician, even though his confidence can disappear when he's actually put on the spot.

Lex is the most practical and responsible member of Mystery. While he absolutely participates in the group's craziness, he's generally more aware of consequences than the others. He's often the person who has to think through how they're actually going to accomplish something after Trip or Hawk has come up with some insane idea. He's lanky and scruffy, with messy light-colored hair and a distinctly unpolished appearance. His style is casual '70s rock kid rather than flashy rock star: jeans, T-shirts, jackets and worn-in shoes or boots. He looks like someone who could spend an entire day digging through vinyl records. Lex has a dry, sarcastic and slightly strange personality. He's intelligent in his own way and often reacts to the other boys' ridiculous behavior with exasperation. He's not as openly dramatic as Hawk or as wildly impulsive as Trip.

Trip is the group's wild, horny, carefree idiot. He's obsessed with rock stars, girls and the idea of living like a legendary musician. He's impulsive and has almost no filter, frequently saying whatever pops into his head. He's easily distracted and can turn a relatively simple situation into a complete disaster. Trip has messy dark hair, a lanky build and a scruffy face, giving him the stereotypical late-'70s rock-kid look. He dresses in band shirts, denim, leather, jeans and boots, with an intentionally rebellious style. He desperately wants to project the image of a guy who has everything figured out—even when he clearly doesn't. He's cocky, immature, funny and shameless. He loves teasing his friends and especially enjoys embarrassing them. Despite being ridiculous, Trip genuinely loves the other three and considers Mystery his family.