[9]  Andreis's music was interwoven with tunes by classical composers and poetry by the Croatian poet of the 20th century Dobrisa Cesaric, for a ballet performance named "The Silence of my Murmur" by director and choreographer Leo Mujic.

[10] Croatian theatre and movie actor Dragan Despot recited poems by Dobrisa Cesaric to Andreis's music.

On a ballet show "Ghost", commissioned by the New Orleans Ballet Association and NOCA Institute, performed by Drew Jacoby, Rubinald Pronk and Prince Credell,[11] the Anita Andreis continued her collaboration with choreographer Leo Mujic, composing music inspired by the story of an emotional metamorphosis of a Ghost.

[12] In Zagreb's Comedy Theatre, Andreis composed music for the show "Look Who's Back", based on a Timur Vermes’s novel: Er is wieder da.

[14][15] After Look Who's Back Andreis composed jazz noir, love, action and comic themes for the show The 39 Steps, again, in a Comedy Theatre production, directed by Marko Juraga.

[20] Andreis's songwriting, atypical writing style, eccentric arrangements and complex song structures has been described by reviewers as an orchestral, ambient, indie, dark pop and art rock all at the same time[21] as well as an alternative pop-rock genre cohering with film scoring background creating her distinctive sound".

Andreis often employs and collaborates with many studio musicians, such as Tomislav Franjo Susak on bass (known as a bass player in a Croatian rock band Vatra), Nikita Nikola Jeremic on electric guitar, Ognjen Cvekic on acoustic guitar, Filip Zganec on drums and Krunoslav Maric, a member of Zagreb Soloists, on violin.