The bigger, the better (I guess)... Many dedicated artists go through hard times, especially if they are adamant about their art and refuse to do "regular" jobs. I respect anyone who makes their own path, or refuse to join The Establishment. Sometimes, it happens after the success, Danny Kirwan for example. Just for clarification, I consider singers musicians. The more details - the better.. Did someone squat? Sleeping in a shelter? Under a highway, library, etc?
Ben Shepherd from Soundgarden apparently said he was homeless before their reunion. But a PR swooped in, took him off press duties, and said he was between girlfriends, or something. Which doesn't sound much better.
Donovan was homeless at the beginning of 1965 and appeared at Newport folk Fest by the end of that year. His career took off quickly.
Marianne Faithfull. After her '60s pop chanteuse period with Mick Jagger and before her gravel-voiced career resurgence. Strung out on heroine, she could have very easily died during that period.
Thought I read that Sly Stone was Homeless for awhile. Also, hard to believe, but Bernie Worrell, as seems like he was always active recording with other Music Artists until his Death a few years ago(even worked with a Music Artist recently from Japan who made FUNK Music), as his Keyboard Wizardry was always in demand beyond his work with P-FUNK and Solo Albums.
It seems like session musicians get paid the least and the minute they don't have work, they're broke.
Dutch rapper Lucien Witteveen, who, under the name M.C. Miker 'G', and together with DJ Sven, scored a hit in lots of countries with 'Holiday Rap' in 1986. Aged 19 then, he had lots of money in the bank and spent it all quickly on gambling and hard-drugs. Became homeless and had to sleep on the streets for years. Is doing a bit better nowadays although still being watched.
Sly Stone was living out of a van a few years ago, I believe. Edit: I see someone posted it already (I overlooked that before posting my response.)
Apparently Chris Wilson of The Flamin' Groovies came pretty close recently. But the GoFundMe campaign referenced in this thread seems to have forestalled it.