STANDOUT TRACK:

“Choo Choo,” a retro-soul number featuring urgent vocals from band leader Caz Gardiner, who sings about packing her bags, catching a train, and riding to meet her man. “When we’re together, there’ll be no slack/No lookin’ back,” she sings, while keyboardist Bill Dempsey intensifies the can’t-wait-to-get-there mood with some upbeat Hammond-sounding riffs. (The song can be heard at myspace.com/ambitionsdc.)

MUSICAL MOTIVATION:

Gardiner, a downtown D.C. resident, says the song is a response to Sam Cooke’s jaunty 1964 hit, “Ain’t That Good News.” Cooke sings about getting a letter from his woman, who apologizes for splitting town impulsively. “I’ve always thought that song was so cool, the way the female is coming back to him, and he’s excited and meeting her at the station,” she says. “One day the melody for ‘Choo Choo’ just popped into my head, and I thought…I could be the girl coming back, and the lyrics just came to me.”

ROCK STEADY:

Four-fifths of the Ambitions’ members—all of whom are in their 30s—played in local ska groups before forming the Ambitions in 2005. Gardiner, bassist Jorge Bañales, and drummer Sean Hissey were in the Checkered Cabs, and guitarist Kelly Ann Marshall was in Eastern Standard Time. Gardiner says the genre shift was perfectly natural and that every member has a hand in composing the Ambitions’ songs. Using Cooke for lyrical inspiration, meanwhile, would’ve been a no-brainer in any situation, she says: “I can listen to any one of his songs and just find every word, every note, every feeling completely engaging.”­ —Joe Warminsky

The Ambitions play the Black Cat on Friday, Dec. 7.