One can only imagine the bittersweetness of finding a lost artwork from a tragically departed spouse. But Eva Svensson, widow of Swedish piano sensation Esbjörn Svensson (1964-2008), translated feelings of loss into action after hearing this fully realized solo piano album in her late husband’s digital archives. It took time, but Svensson stayed on the case and got HOME.S. out to the world, appending her own Greek alphabetic titles to the nine unnamed tracks. Before Esbjörn’s sudden death while scuba diving at age 44, he had gained wide acclaim with e.s.t., the trio he led to international success with such albums as From Gagarin’s Point of View, Good Morning Susie Soho, and Seven Days of Falling. To the posthumous trio releases Leucocyte and 301, we can now add Svensson’s first and only solo piano document, probably recorded at home though no one knows for sure. “Gamma” and “Eta” are the longer, more exploratory pieces; “Delta” is short but demanding, full of momentum and moving parts that favor the piano’s middle-to-low register. “Zeta” has a Moonlight Sonata-ish feel, while “Beta” has a loose and lyrical singing quality as it sways out of tempo. Svensson’s touch is varied and expressive, his virtuosity spilling out on a piece like “Epsilon.” The long, natural decays at the end of “Zeta” and “Eta” have an uncanny effect as they fade gradually to nothing, as if Svensson is parting our company.