>>212268440NSYNC's music was based on black genres: RnB, funk, hip-hop, soul.
They were genres the guys enjoyed performing, and that's why No Strings Attached and especially Celebrity were albums that diverged from the basic boy music of their debut. They made both of those albums after leaving their original management and label, because they wanted some control of the songs they were making. Note that they left major label RCA to move to an indie, Jive, which was known for making RnB and hip-hop albums.
Timberlake was thus seen as a credible beatmaker and they went out of their way to get producers like The Neptunes.