Hey @Abrahams! I think the Funnel chart will be helpful for this. Create a Funnel chart where the first event is Session and the second event is Purchase. In the examples below, I am using Play Song or Video as the first event and Purchase Song or Video as the second.

1. The Frequency feature will show you how many times a user performs Play Song or Video before Purchase Song or Video: https://analytics.amplitude.com/demo/chart/new/595mdf1
2. The Time to Convert feature will show you how long it takes from when the user first performs Play Song or Video to Purchase Song or Video: https://analytics.amplitude.com/demo/chart/new/n89cdvw 

I’m not sure how you define Session in your instance, but what we do is we run the following function to define a variable called amplitudeNewSession:

function(){
var amplitudeNewSession = amplitude.isNewSession();
  return amplitudeNewSession;
}

When amplitudeNewSession = true, we fire an event called “Landing Page View”. When it’s false, we fire the regular “Page View” event. 

Hope this helps!