Cellist Alex Greenbaum played a noontime solo recital Friday at the San Diego Central Library to inaugurate Art of Elan’s new monthly concert series there. In words of welcome, Kate Hatmaker, the San Diego musical organization’s Artistic and Executive Director, outlined the musical intentions of this project, noting that the expansive cityscape view of downtown San Diego from this spacious corner room on the library’s ninth floor inspired her to propose this series to the Central Library. Greenbaum titled his engaging program Sarabandes and Sojourns, a collection of a dozen short movements that spliced works by contemporary and 20th-century composers…