How can i delete the vocals in a song? I only want to hear the melody / Hoe kan ik de zangpartij deleten uit een bestaand nummer zodat ik alleen de melodie overhoud?
I'm afraid once the song exists in form of a mixed-down audio file or CD, it's not possible to isolate and remove one element anymore. You would need to have access to the original multitrack recording (e.g. on multitrack tape or as a project file for a sequencer software) in order to be able to simply remove or replace a vocal or instrumental track. The closest thing to this you can do with the mixed-down result of an audio production is the filtering out of certain frequency bands (e.g. the "karaoke" effect), which can muffle elements of the song. However, this doesn't work equally well with all audio material, generally doesn't completely remove the undesired element and usually also affects other elements, resulting in a general deterioration of the music's quality.
It can be done in many cases... Raltaro is right in that once a song is mixed down; isolating individual components is usually not possible.
Vocal tracks are usually recorded in stereo right down the middle of the mix - this gives you a good chance of removing the vocal track.
Though there are a couple of ways to do this, the easiest is to search for free VST plug-in for removing vocal (karaoke) and use it with Magix. Many are available and work well. You will usually have artifacts left in the song but in many cases it's hardly noticeable.