A music service using Melded will act as a 'data controller.' According to ICO regulations regarding the role of a data controller...
You decide to collect or process the personal data.
You decide what the purpose or outcome of the processing is to be.
You decide what personal data should be collected.
You decide which individuals to collect personal data about.
You may obtain a commercial gain or other benefit from the processing.
You may be processing the personal data as a result of a contract between yourself and the data subject.
The data subjects may or may not be your own employees.
You make decisions about the individuals concerned as part of or as a result of the processing.
You exercise professional judgement in the processing of the personal data.
You have a direct relationship with the data subjects.
You have complete autonomy as to how the personal data is processed.
You have appointed Melded as the processors to process the personal data on your behalf.