Spotify is a digital music and podcast streaming service. The service is either free with advertisements or paid. You can access your music today on almost any device, simply sign up here.
The universal solution on computers of any operating system is to use the Spotify Web Player. However, more comfortable to use is the desktop app.
While it may be easier to install Spotify on other Linux distributions, it is not hard on Solus either. The following lines of code, which were provided by the Solus Help Center, need to be run in the terminal.
First of all I would like to say that it is important for content creators (e.g. musicians) to get paid for their work and thus you should either support them.
You can do this by buying their albums and merchandise, but also by listening to their content on streaming platforms like Spotify. However, you don't support them unless you endure the ads or purchased a premium account.
So yes, blocking ads on Spotify is immoral. However, if there is no way you can pay for it, or you are supporting the groups you listen to in another way, there is a way to block the ads.
For this, I recommend editing the /etc/hosts file and adding the following lines (Source). A restart is required for the changes to take effect.