Singer-songwriter Aimee Mann is a former Til Tuesday frontwoman, Paul Thomas Anderson muse and a pioneering indie label founder who is now working on a musical version of her 2005 concept disc, “The Forgotten Arm.”

Raised in Richmond, Mann considers the Birchmere (where she plays April 12 and 13; she’s at the Recher Theatre in Towson, MD on April 10) to be practically a second home. She talked to Click Track about the long-gestating musical and the pains and pleasures of songwriting.

You’ve been working on this musical for years now, right?

My understanding is that any musical takes years and years to develop and write, even before it gets produced. Where it stands now is I’ve been writing new songs for it and it’s based on one of my records called “The Forgotten Arm.” I’m writing [new songs] with my producer Paul Bryan….We were working with a writer who was writing the book, but that hasn’t worked out, so we have to find another writer. But at this point we want to make a new record, so I’m writing songs for a new record.

Are these re-worked songs from the “Forgotten Arm” album, or totally different ones?

Totally different songs… It’s a fun project. Who knows if anything will ever happen with it, but it’s kind of fun to have a totally different project from the things I’m used to doing.

Have you thought about writing the book yourself?

I don’t think that’s possible. It’s too specific — there’s a specific way of writing and that’s not the kind of thing I can do, anyway. It takes a lot of skill to keep a story interesting from scene to scene and you really have to know what you’re doing.

How would you describe the [sound of the] songs?

I really like kind of old-fashioned musicals. I think some of the songs that I’m writing are halfway between — they’re definitely a little closer to a traditional musical style, partly because I really like that and partly because in a musical you have to impart information in a different kind of way because the characters are basically talking to you through the songs… There’s not much room for ambiguous lines, which is what makes pop music interesting, that sort of ambiguity or ambiguous phrases that hint at things. You have to be really specific in a musical. It’s an interesting challenge.

Your style seems to be so natural-you write the way people really speak, which would seem to be the opposite of what musicals do. There’s something inherently unnatural about people bursting into song.

I do like to write in a more conversational way, and I think that in a musical, for me, I try to keep that idea, but just expand it.

When you’re writing songs for a new album, do you find those songs bleed together with songs for the musical?

Not so far… What I do is I make a tape of just sort of musical snippets, little melodies and things. It’s a different headspace.

Do you enjoy the process of songwriting? Or does it feel like homework?

There’s an aspect of it where it feels like homework but once you start it doesn’t feel like homework anymore. There’s definitely [an aspect of] making a list like, “Okay, I’ve got to write a bridge for this song, I’ve got to finish that song and I need to finish the lyrics to this song.” But once you focus, you’re in that world.