First recorded by The Superiors (1987).
Hit version by New Kids on the Block (US #1/UK #2/CAN #1/1990).
From the wiki: “‘Step by Step’ was written by Maurice Starr, discoverer of The New Edition (1982) and New Kids on the Block (1984), and was originally recorded by one of Starr’s later group creations, The Superiors. ‘Step by Step’ was released as a Motown single in 1987 with no apparent chart impact.
“But, in 1990, ‘Step by Step’ became an international hit and the biggest-selling hit single from New Kids on the Block. The song spent three weeks at #1 on the U.S. Billboard Hot 100 and was eventually certified platinum; it also spent two weeks at #1 in the Canadian Singles Chart, and reached #2 on the UK Singles Chart. ‘Step by Step’ has also been voted #4 in a Smash Hits poll of Best Boyband songs…Ever, #5 in NME’s Top 50 Boyband Records chart (2005), and also made the list of the Top 30 Guilty Pleasures on About.com’s music site.”
New Kids on the Block, “Step by Step” (1990):