Sampling in music involves taking a section of audio from an existing song, and then reworking it into the creation of a new track. A famous example is for instance Madonna's "Hung Up", which uses a sample from ABBA's "Gimme! Gimme! Gimme! (A Man After Midnight)". If you want to legally sample a section of another artist's song in your own work, you are first required to get permission or a "sample clearance". Sample clearance is the process of getting permission to use portions of existing audio in new music. You need permission for the use of both the master (the actual recorded audio) and for the composition (the underlying musical work) of a song, sound, or performance. You can find more information on how this works here.
This is also the case for using beats in your own songs that have been made by producers or other beat makers. If you purchase a beat online, you can use it in your song and distribute it, but make sure to get a license detailing that you can use the beat in your own work. These days, a lot of people can purchase the exact same beats online, meaning that there might be a lot of other artists using the same beat as you. To prove that you're not infringing someone else's copyright, it's important to get the proper license in place.
Please note: if you use royalty free samples, your music cannot be delivered to YouTube Content ID. This is because you must own 100% of the music you are submitting to YouTube's Content ID service. So beats that contain unedited samples, loops or royalty free music are not allowed and cannot be monetized.
It is allowed to upload and deliver cover songs via Make Waves. The most important thing, is that the original artist is credited in the metadata. When you are uploading your audio and filling in all the required information for your track, you can find the following toggle:
When you select that the track you are uploading is a cover, it then gives you the option to specify the original artist and the original track name.
Spotify and Apple also have some specific title formatting guidelines for cover songs. They say that track titles for cover songs must not mention the original artist. For example: "Born This Way (Originally Performed by Lady Gaga)"
This is not allowed. You can use the same title for your cover song or remix, but then you would only mention Lady Gaga in the original artist field which is specified above.
For remixes and mashups, however, you do need to make sure you have the permission from the existing artists to deliver the track(s) to DSPs.
Creating a remix of an original track without getting the proper license is not allowed. To remix a song legally, you'll have to get permission to use the song from the original songwriter(s), publisher(s) and owner(s) of the song recording. This is the best route to avoid any legal trouble.
When you do have this permission, you can specify the track is a Remix under the same toggle as the one used for Covers and mention the original artist and track name.
If you have more questions about this, feel free to reach out to email@example.com.