Carey LaMothe studied horn at the University of Washington with David Kappy, earning a Bachelor of Arts and Bachelor of Music in French Horn Performance. After graduation, Carey moved to Los Angeles to pursue a freelance career. While living L.A., Carey taught elementary school band and lessons in French horn, trumpet, trombone, euphonium, and piano. She performed and toured with String Theory Productions and played in various ensembles. Recording credits include Under the Covers, Vol. 1, a collaboration between alternative rock artist Matthew Sweet and Bangles singer/guitarist Susanna Hoffs.

In addition to her regular performances with Octava Chamber Orchestra, Carey is a member of the Orchestra Seattle and Seattle Chamber Singers horn section. She previously held a principal role in Thalia Symphony and often plays for other local ensembles.