Years ago, everyone used 4 string basses. Then, the 5 string bass was invented, and it was known as an extended range bass (ERB). Now, it seems that 5 and even 6 string basses aren't even ERBs anymore. They are almost staples to a bassist's collection. What will happen 20 years from now? Will a 4 string bass even exist? Will 6 string basses be normal? Will there be a 24 string single course?????? 
