Conversation so far:
What year did Lou Gramm leave Foreigner?
Gramm decided to leave the group in May 1990.
Why did Lou Gramm leave Foreigner?
Gramm announced his departure from Foreigner in May 1990 due to differences with Jones, and to focus on his solo career.

Question: What work was done solo?
Self-contained rewrite: What work did Lou Gramm do as a solo?