“Sugar, Butter, Flour… “

This is the first line from Sara Bareilles’s most recent release from this past November: What’s Inside: Songs from Waitress. If you didn’t know that What’s Inside was a concept album for the new musical Waitress based on the 2007 film starring Keri Russell, you would probably be very confused as to why she’s singing about the basic ingredients for a pie crust.

In this case, Bareilles is singing as Jenna Hunterson, a waitress and pie expert at a diner in the American South who is stuck in a loveless marriage with an unwanted pregnancy. The opening song, “What’s Inside,” flows directly into “Opening Up.” It has that distinctive Bareilles sound, but it’s also very clearly the act one opener for a musical.

Waitress is Bareilles’ first musical, and it’s opening on Broadway. The cast, led by Tony award winner Jessie Mueller (Beautiful: The Carole King Musical) as Jenna, also features Drew Gehling (Jersey Boys), Keala Sette (Les Miserables), Tony nominee Nick Cordero, Christopher Fitzgerald (Wicked), and Kimiko Glenn from Orange Is The New Black. The musical has only recently gone into rehearsals, with an opening set for April 24 at the Brooks Atkinson Theater, and therefore the cast hasn’t recorded an album yet. Bareilles released this album as a preview of what was to come.

There are 12 songs on What’s Inside: ten solos by Bareilles and two duets with Jason Mraz. They all very clearly tell a story, but with only two voices, some of the context gets lost. It’s very hard to tell which characters sing what songs when Bareilles is the only voice on majority of them, but the music itself is fantastic.

Bareilles released the act two solo “She Used to Be Mine” as the lead single; it’s Jenna’s big moment during the show. She looks back on her own life using the third person “she” when referring to herself. The single peaked at 26 on the Billboard Adult Top 40.

“When He Sees Me,” track number four, is the point when it’s clear that What’s Inside is a piece of musical theater. It’s a fun-filled, wordy number that once transferred to the stage will make a showstopper. “Sugar, Butter, Flour…” comes back during “Soft Place to Land,” a haunting ballad.

The fun part of a concept album before the premiere of a show is getting to listen to the songs and just let your imagination run a little bit in terms of what this number will look like on the stage with sets, costume and choreography. Songs like “Never Getting Rid of Me” and “I Didn’t Plan It,” which will be sung by Sette during the show, will certainly have great choreography to add to the number. “I Didn’t Plan It” falls a bit flat towards the end, with a guitar solo. When transferred to stage, the solo may be replaced with something bigger using the pit orchestra.

The best thing about What’s Inside is that it isn’t a massive spoiler in terms of content, because so much context is left out surrounding all of these songs. “Bad Idea,”the first duet on the album, has more plot in it than the seven songs that came before it. If you’re really worried about spoilers, avoid the last two tracks: “Everything Changes” and “Lulu’s Pie Song.” Other than that, What’s Inside: Songs from Waitress is a stellar piece of pop-musical theater fusion that works extremely well for a singer/songwriter like Bareilles.