AudD recognizes music in microphone records and in audio files.
It costs from $2 to $3.7 per 1000 requests
Also AudD recognizes music that your users sing or hum
Search by excerpt from the lyrics in DB with 4 million songs
Some have a lot of user-generated content in their apps and use AudD to detect if there is a music.
Some help their users with lyrics searching using AudD.
Some use AudD to calculate the statistics of offline music plays.
Some (as example, Vibes) use AudD to recognize music in their own applications.