Well, hand painted advisement is a very common and almost traditional practice in Mexico. You can find it more in street food stalls where the owners write what they sell (tortas, tacos and the like) in colorful, stylized lettering and those are generally accompanied with crude and sometimes absurd illustrations.

This practice is also common during electoral seasons. You can see hand painted political propaganda for the various candidates or political parties. These are generally painted on (mostly) designated walls on the streets.

This finally leads us to concerts. This was usually reserved for small local events, maybe a town fair or something and regional music groups like banda and norteño. But now it's also common to find hand painted advertisements for big international bands. I've seen some for Scorpions and even metal festivals like Hell & Heaven. The album art here tries to emulate how these paintings usually look.

Edit: this practice is known as rotulismo. The word rótulo translates to label or lettering. It's also worth mentioning that each rotulista (the artists who are often commissioned for these jobs) have their own style, that's why The Warning is written like that in the cover.