In Japan, observation of the seasons is an ingrained cultural trait that not only forms the basis of haiku poetry and many classic works of art, but also marks the calendar for cultural ephemera from special-edition Kit Kats to alcoholic drinks to pop music. Since summer is now at full burn, here are my Top 5 seasonal girl-pop hits from the genre's golden age:

Chiyo Okumura — "Kitakuni no Aoi Sora (Hokkaido Skies)" (1967): Japan's pop world never really embraced rock 'n' roll or R&B in the way its Western counterparts did, but the kind of clinical, guitar-twanging instrumental music pioneered by groups such as The Shadows, known in Japan as eleki, was nothing short of a phenomenon in the 1960s, and undisputed kings of all they surveyed were The Ventures. This 1967 hit takes a Ventures tune and wraps a proto-enka melody around it, with a raw, sultry edge courtesy of the deep, rich vocals of '60s-style icon Chiyo Okumura.

Saori Minami — "Natsu no Kanjou" (1974): Okinawan pop goddess Saori Minami's career was always caught in a struggle between those elements who wanted to make her into a pure idol singer and those, including Minami herself, who wanted her to do something more mature. Fortunately for Minami, her songwriting team of Mieko Arima and Kyohei Tsutsumi were in the latter camp, and together they came up with this magnificent piece of subversively hard-rocking, synth-abusing, R&B-influenced bubblegum.