The alarm clock blares at 5 a.m. But the alarm isn’t necessary, because falling asleep is difficult for sophomore wide receiver James Grisom, so today he’s lying in bed, staring at the ceiling, waiting for the ringing to kick off the start of his 21-hour day.

It’s March of 2012. Football meetings start in exactly an hour, and he needs to trek the three miles from his apartment at University and San Pablo to Memorial Stadium. There’s no time for breakfast, so he has to sit through another morning meeting on an empty stomach and the customary zero to three hours of sleep.

The meetings end at 8 a.m., but there’s no time for a nap; class starts right afterward and goes on until the afternoon. And he can’t head home, because there’s homework to do, and afternoon practice to attend, and an occasional mentoring session in Oakland, and weekly Bible study, and a work-study job keeping him at work until 1 a.m. at the earliest. And he needs to make time for his music.

Music is practically hard-wired in his brain — as a young child, he used to fall asleep to the sound of his father playing the piano downstairs. Grisom’s mother calls his ability to play the piano a gift from God.

“I don’t know what it is,” Grisom says. “But music takes me to a whole other place. It has this really weird effect on me. I don’t really understand it.”

Grisom’s father brought him into the world of music with the purchase of a small studio, complete with a tiny drum kit, for him and his brother.

At first, Grisom messed around with making basic hip-hop beats. The connection wasn’t instantaneous. It arrived later, in ninth grade, while playing the video game “Ninja Gaiden” on his Xbox 360. Midway through the game, he began to pay attention to the background music.

“It was like an epiphany,” Grisom says. “I was fighting the boss and getting really into it. And then I started noticing the music. I would re-play that fight over and over because I loved that music so much.”

He asked his father to teach him the basics on the piano, and soon he was composing his own music. He never took a single lesson. His mother once asked him how he wrote his music.

“I just play what’s in my head,” he responded.

He flirted briefly with the idea of producing rap or rock music but soon became enamored of film and video-game scores. For inspiration, Grisom dabbled in genres of all kinds: meditation music, instrumental guitar and modern hip-hop.

His eclectic influences cohered to a singular goal: becoming the best musician he could be. The dedication paid off — he now plays the piano fluently and has an entire catalog of songs on his personal SoundCloud page. When he can find time, he assists a local filmmaker named Sheri Shuster in composing a score for her documentary on human trafficking.

But ask Grisom why he calls composing his dream job, and he can’t quite put his finger on it. He thinks his attachment to music connects, in some way, with his spirituality — he likens the feeling of sitting down at the piano to a religious experience.

“Over the past week or two, I’ve been talking to some of my friends, trying to understand why music has this effect on me,” Grisom says. “I’ll just be listening to something, and I start thinking about life and, like, appreciating everything around me. It’s out of this world.”

It’s hard for Grisom to find time for his music these days. He accepts the compromise, because if there’s anything in his life he cares about as much as music, it’s football.

“I feel like I came out of the womb playing football,” he says. “It’s always felt like something that’s meant to be.”

Around fourth grade, Grisom set his mind on playing football for the local Pop Warner team. His father refused to let him play. Grisom begged. His father held firm — until he couldn’t.

One spring morning, the elder Grisom threw him in the car and drove him to the Pop Warner sign-ups.

Speedy and undersized, the young Grisom fit well at receiver and cornerback. He terrorized opponents and had a knack for stepping up under pressure, earning the nickname “Big Game James” from an uncle of his.

Upon arriving at Lynwood High as a freshman, Grisom switched positions twice: On offense, he moved to quarterback, and on defense, he became a safety.

During his junior year, his strong play brought representatives to watch him from Fresno State and Washington, among other schools. But a separated shoulder dampered his senior-year production, and the burgeoning interest from Division I schools evaporated.

When former Cal running backs coach Ron Gould hinted at a chance to walk on, pending his acceptance, he made UC Berkeley his top choice.

Unfortunately, former Cal head coach Jeff Tedford seemed uninterested in letting him play receiver. Grisom saw the field occasionally as a special teams player, but he remained on the periphery. Despite the insane schedule that comes with the territory of being a walk-on, Grisom pushed on.

The hire of head coach Sonny Dykes was like a defibrillator to Grisom’s receiving career. Dykes’ offense scratched the tight end position and called for four or five receivers rotating in and out of the game with regularity, forging a sliver of an opening on the depth chart for Grisom.

He starred in his first camp under Dykes, providing one of the highlights of the annual spring scrimmage with an acrobatic 45-yard touchdown catch. A lifeless situation found its heartbeat.

Early in the morning on Aug. 23, prior to the last practice of fall camp, Dykes called a team meeting to collect votes for the election of the team’s captains. After the vote, he mentioned that there was a special announcement: Grisom had received a full scholarship.

The room erupted in applause.

The alarm clock blares at 5 a.m. He’s eaten a good breakfast, so he’s rested and energized for his 7 a.m meeting. He no longer lives three miles from the stadium; he’s found a house with his friends on Southside.

It’s September of 2013. Classes continue deep into the afternoon, and practice finishes at 7 p.m. He heads straight home and starts working on composing a song for a scene Shuster described to him earlier that week over coffee. He will consider the mood of the scene, the camera angles and the context.

And he’ll fall asleep as soon as his head hits the pillow at 10 p.m, a lifelong dream materialized.