Music has changed a lot over the past 30 years, including how we purchase it. Below is a helpful graphic that allows you to see just how much has changed. For years, cassettes, vinyls and CDs absolutely dominated the market. CDs, of course, have had the longest reign at the top for basically close to 20 years. It had only been in the past 10 years that digital sales have begun to change the course of music sales. Digital singles also take up a significant portion of the chart, as well as ringtones/ringbacks, digital albums and streaming services.
Source: Digital Music News