Mellow Yellow is actually more diverse in its sounds than Sunshine Superman, drawing on some of the same era's better follow-up material but also reaching back somewhat further for repertory. It was, as one could rightly guess, a by-product of the late-1966 hit title track, but the songs dated back in some instances as much as a year, to a point prior to Donovan's having made the leap from folk to pop artist. "Mellow Yellow" itself was cut after "Sunshine Superman" and boasted one of the earliest arrangements by John Paul Jones to achieve international recognition (although not without some resistance from Donovan himself), with its broad, biting brass sound. The next two tracks, however, reached back to the singer-songwriter's earlier acoustic/folk songbag, and a very different point in his career -- the reflective, somber "Writer in the Sun" was written in Greece during the spring of 1966, when it looked as though Donovan's career was in danger of ending due to legal problems. By contrast, the hauntingly beautiful "Sand and Foam" dated from a somewhat happier visit to Mexico. "The Observation" manages to quote the album's title tune obliquely in its bass-line, even as the singer veers close to a beat-style poetry recital. "Museum," which sounds at times almost like an artier sequel to "Sunshine Superman" and a precursor to "There Is a Mountain" in its word pattern, breaks up the succession of blues settings on the album's second side, as does the jazz-flavored "Hampstead Incident." The album ends with "Sunny South Kensington," an upbeat number driven by radiant (albeit name-dropping) lyrics, Eric Ford's crunchy guitar (emulating his contribution to "Sunshine Superman"), Shawn Phillips' sitar, and an economical arrangement by John Cameron (who also plays the harpsichord).
AllMusic Review by Bruce Eder