The pop star, 21, will determine which cities she includes on her Neon Lights tour by the number of Shazam tags that are generated for her current single - also called Neon Lights.
The tour will be shaped around the cities that generate the most tags, but not all markets will make the tour.
Lovato said: "I am thrilled to collaborate with Shazam on such a unique promotion which puts my future in my Lovatics' hands by allowing them to pick which cities I visit!
The promotion begins today and will run for the next three weeks. The tour will be the singer's first European tour in five years.
The successful dates and locations will be announced at the end of May when Lovato is in the UK.
The singer recently announced a one-off show at London's Koko on June 1, with tickets selling out in seconds.
