DreamWorks has signed on Catherine Keener to co-star in the music film The Soloist, according to Variety.

Jamie Foxx and Robert Downey Jr. have already boarded the project, which Joe Wright (Atonement) will direct starting in January.

The story centers on Nathaniel Ayers, a homeless musician with schizophrenia who dreams of playing at L.A.'s Disney Hall. The screenplay, by Susannah Grant (Erin Brockovich), is based on a 2005 series of articles by Los Angeles Times columnist Steve Lopez.

Downey Jr. will play Lopez, who found Ayers (Foxx) on the streets of downtown Los Angeles. Keener will portray Lopez's wife.