Conversation so far:
Where does George Gershwin's lineage descend from?
Gershwin was of Ukrainian Jewish and Lithuanian Jewish ancestry.
Are there any other interesting aspects about George Gershwin's lineage?
His grandfather, Jakov Gershowitz, was born in Odessa and had served for 25 years as a mechanic for the Imperial Russian Army to earn the right of free travel
Does George Gershwin have any other known linage?
Roza Bruskina, the teenage daughter of a furrier in Vilnius. She and her family moved to New York due to increasing anti-Jewish sentiment in Russia, changing her first name to Rose.

Question: What side of his family is Russian
Self-contained rewrite: What side of George Gershwin's family is Russian?