Electric Lady Studios, in Greenwich Village, is a working music museum. The Fender Twin amplifier that the studio’s onetime owner Jimi Hendrix brought to work before his 1970 death remains, as does an electric piano Stevie Wonder used on an astounding run of records. There’s a keyboard Bob Dylan played in Muscle Shoals and several lurid murals by the painter Lance Jost, originals depicting interstellar travel and Aquarian-age sexual exploration.

But Lee Foster — the former intern who became the space’s co-owner in 2010, after helping rescue it from financial ruin — keeps his drawings by the singer-songwriter Daniel Johnston in a small safe in the corner of his office, each page bound in plastic in a lime-green three-ring binder.

The shelves in Daniel Johnston’s kitchen are completely filled with figurines and keepsakes. The house remains largely as he left it before his 2019 death.

“It has nothing to do with financial value,” Foster said in his art-lined room last month, as afternoon slipped into evening. “It is so meaningful that, even if it was for that hour or three when he was sitting down to draw, it was all he was thinking about. There’s a little bit of his soul in there.”

Soon after Johnston’s death in 2019, at 58, Foster became the unexpected custodian of Johnston’s unexpectedly enormous art archive. His career hamstrung by bipolar disorder and stints in psychiatric hospitals, Johnston first found acclaim as an unguarded and guileless songwriter in the late ’80s with tunes that cut instantly to the emotional quick.