Trap started in the early 2000s, and it was much closer to standard hip hop than the trap we know today. The only main difference between the two at this time is that trap music had different lyrical content. Trap was about creating and selling crack cocaine in a home dedicated to the cooking/selling of crack cocaine, which was known as a trap. It still used the same sampling techniques, but as time went on, producers started making the bass heavier and heavier. Important artists from this time include Young Jeezy, T.I., and Gucci Mane. The breaking point was when the big producers of Atlanta (Zaytoven, Shawty Redd, etc) started to lengthen the release of an 808 drum machine kick, which when played on speakers that could play low frequencies, made for very heavy bass. They then started using this lengthened 808 kick as a bassline, creating the backbone of modern trap music. The quickly timed and constantly changing rhythm hi hat patterns followed. during this change, the instrumentation started to abandon traditional hip hop stylings, and move towards a less sample based, more instrument based production. The producers started relying heavily on strings and brass to create this new heavy sound. Eventually, each producer would find their own sound, making trap a very diverse genre. Over time, trap has become very experimental, leading to the many different styles we see today.