Why so many rappers?
Recording costs are the reason there are so many rappers and producers, not the internet.
Music technology has rapidly advanced in the past 20 years. Before, you had to record to a tape reel. So if you wanted to get signed by handing out demo’s, you would have to pay a studio to record it there. Cost & equipment were the biggest barriers to entry for an unsigned artist. (Magnetic tape recording was invented by the Nazi’s :()
As this was the only way to record a professional sounding demo, studios knew they could charge as much as they wanted. However, some studios offered a demo deal, where they would record your demo for free but if you got signed they would be entitled to a percentage of the advance fee.
With the development of Pro Tools, Cakewalk, Goldwave and other recording software, you could record, sequence and mix your songs to .wav and .mp3. These files could be burnt to C.D or Mini Disk, bypassing the analogue form of recording.
Affordable home computers & laptops contributed to the rise of the home studio, as producers didn’t have to pay for studio time to use expensive synthesizers and drum machines. Propellerhead Reason and FL Studio provided producers with their own digital audio workstations.
Professional equipment such as the Shure SM58 could be purchased cheaply for second hand. (USB microphones can also offer a quality sound when recording at home.)
The internet helped to provide a platform to upload the recordings, obtain free recording information and try to make some new fans.