Conversation so far:
Can you tell me about Harry Nilsson's Maverick years of 1973-1979?
Harry Nilsson's disregard for commercialism in favor of artistic satisfaction showed itself in his next release, A Little Touch of Schmilsson in the Night.
Did Harry Nilsson's A Little Touch of Schmilsson in the Night become popular?
Although Harry Nilsson's album met with only modest chart success, it is often regarded as the finest example of his virtuosic singing.
So what eventually happened with Harry Nilsson after A Little Touch of Schmilsson in the Night did not do well?
Harry Nilsson moved back to California in 1973.
What did Harry Nilsson moving back to California lead to?
After Harry Nilsson moved back to California, he and John Lennon were able to eventually rekindle their earlier friendship.
Are there any other interesting aspects about Harry Nilsson's Maverick years of 1973 - 1979?
John Lennon was intent upon producing Harry Nilsson's next album. However, their time together in California became more for heavy drinking than it did for musical collaboration.

Question: What else did he do?
Self-contained rewrite: What else did Harry Nilsson do with John Lennon during the years of 1973 - 1979?