Whether it’s Big Sean’s provocative punchlines aboard the synthy bounce of “Open Wide” or HAIM’s glistening harmonies on “Pray to God”, Motion has the feel of a VIP pop party. But despite the bustling guest list—which also includes Gwen Stefani and Tinashe—Calvin Harris’ fifth album is more than just a showcase for his imposing contacts book. “Slow Acid” shows his ear for ‘80s-tinged instrumental fire and “Summer” tempers club bombast with the Scotsman’s plaintive vocals.