All official releases by MELOD can be found on Spotify. They are also on other platforms like iTunes, Beatport, YouTube Music, Amazon Music, Apple Music and many others.
Unreleased track previews, commissions, free downloads and other such things can be found on SoundCloud
There is also a large (over 1000 tracks) curated playlist by MELOD with more music added multiple days a week.
If you are still craving for more, you could also try the predecessor of MELOD, Melodïcore. All of the official releases by Melodïcore from 2013 forwards can be found on all of the same platforms as MELOD.