We play a lot of music, different genres and at different file resolutions to get an idea of how well portable music players. If there are features then we make sure we fiddle with them until we're satisfied. We gauge on how long their battery life is and whether the player holds up to the manufacturer's claims. We try them on their various wireless connections to see if they offer a smooth performance, and we'll delve into their sub-menus and see if they work as they're meant to. Of course, it always comes back to the music. Portable music players are tested by reviewers who have a love of music, a knowledge of sound quality, as well as a context of the market. We'll compare to similarly priced rivals, so when we recommend a particular model, it's among the best you can buy for the money. Obviously, we know not everyone has the same taste in music, so we won't only test with the same perfectly mastered album, but with a variety of genres and file qualities, from MP3 to Hi-Res FLAC. Find out more about how we test in our ethics policy.