"Playing music, and at all hours of the night," remembers his daughter Kimberly Dela Sierra.
Ruben has a simple explanation.
"For myself, it's in my blood, so I enjoy doing it, he says.
But several months ago, the music suddenly stopped. COVID-19 had invaded not just Ruben's body, but his lungs. The wind he once used to push out notes from the likes of Charlie Parker to Kenny G., was now dangerously weak. The beginning of a months-long battle at Stanford hospital, which he describes as feeling like being in prison.
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"It became harder for him one to two weeks into his stay at the hospital because he was not expecting that to happen, none of us were," says Dr. Nidhi Rohatgi, MD, a clinical associate professor of medicine at Stanford.
Dr. Rohatgi says both staff and Ruben's family worked to keep his spirits up, while doctors worked on his condition. But as the weeks turned into months the weight of his struggle grew. At one point, Ruben texted his family saying that he'd told his doctors, if necessary, he wanted to go peacefully.
"The text put me into a... I've never felt like that before," said his daughter Kimberly in a halting voice.
While communicating daily, Kimberly also asked doctors to add something to his room. A CD player, complete with recordings of her father's music.
"I asked the nurse, please play this CD far away from him so he's not able to turn it off. And they said for some reason his oxygen has gotten really good. And I believe it was from him listening to his own music," she says.
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Slowly, Ruben began to regain his strength, building like one note on top of the other. Even though doctors had told him that returning to instruments like the saxophone might be a difficult challenge.
"I think that was a defining moment when he pulled in all his intrinsic qualities as a survivor, as a fighter. For his family, not for music," says Dr. Rohatgi.
Finally, after a total of 114 days, Ruben returned home to his family in San Jose. They say its important to rebuild his endurance, with the strain on his lungs from the virus. Still, the man who's entertained audiences around the country is determined to find a way to keep going with his craft.
"Just give me a little chance to feel that I'm ready to play for you," says Ruben.
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