AceShowbiz -

Pop-rock star Ashlee Simpson has a new single, which the singer premiered on Wednesday morning, November 21 via her Twitter account. The dark, angst-filled track titled "Bat for a Heart" can be heard in its entirety online and brings in a more mature sound from the 28-year-old artist.

The track kicks off with an unassuming piano tune playing against a steady beat of drum machines and synthesizers. Simpson gets into the song with some feisty, no-nonsense attitude as she blurts out the lyrics, "I'm gonna bang, bang, f***k you up / Twist you out inside of my head."

Simpson then quickly makes an electro-pop shift with more of those synthesizer sounds and drum beats kicking in towards the middle of the track and her singing very bitterly about feeling abandoned and rejected by a lover.

"Bat for a Heart" was co-written and produced by Simpson with writer Linda Perry, who is also known to pen songs for pop diva Christina Aguilera. It definitely shows a much more mature and darker side of the "Pieces of Me" hitmaker which leaves some speculations that she has been doing some rethinking and repackaging of her image during the time that she has been under the music radar.

"I am so excited to share my new music #BatForAHeart with you," wrote Jessica Simpson's younger sister.

The singer independently released the track on iTunes on November 21 and there is no news yet if the single will turn into an entire studio album and no confirmation about an official music video.