Two Parts of a Song
It is important to note the distinction between a musical composition and a sound recording. There's the music composition, which is the intellectual property of the composer(s) who created it, or their publisher(s). It is includes aspects like the lyrics, melody, rhythm, and harmony. Then there's the sound recording, which is the physical and digital property of the recording artist or recording label that produced it. Each one is separately protected under copyright. In some cases, you can register both parts together in the same filing, other times you must file them separately.
Any time you are using a song's sound recording, you are also using the song's underlying music composition.
What Exactly Can I Copyright?
- With regards to the sound recording it is simple. As soon as you create a sound recording, or "Master", you own the copyright to it in its entirety (unless it's a bootleg/sample of someone else's audio). For anyone to legally use it, they would need your direct permission in the form of a Master License.
- With regards to the music composition it becomes less simple. This because there are multiple parts that make up the whole composition, but only some of them are typically protected by copyright.
- Protected Parts (Unique Works)
- Melody - The order and rhythm of pitches that make up the main melody line of a piece of music is considered the unique work of the composer, it is protected. This can extend in part to the distinct melodic lines that also make up the harmonies of a song, referred to as Voice Leading.
- Lyrics - The collection of words in a song, whether spoken or sung, are also considered the unique work of the lyricist and are protected.
- Other Parts (Building Blocks)
- Harmony- The harmonies and chord progressions that make up a song are not considered something we can copyright. If they were, practically 99.99% would be illegal infringement. While distinct Voice Leading is copyrightable, Chord Progressions (like 12 Bar Blues, ii-V-I, C-G-Am-F) are standardly used in all genres of music and do not belong to any one individual.
- Rhythm - In most cases, the sequence of rhythms and "groove" of a song cannot typically be copyrighted. Just like chord progressions, rhythms and grooves are standardly used in every genre. In some genres, it can be argued that a certain rhythm might be unique and distinct. But if you were to extract the drum part from a number of rock songs for example, you would notice they all sound very similar. It would be a difficult case to argue that someone "invented" the backbeat. (If an artist samples the audio of a drum loop from another recording, however, it still belongs to the copyright holder of the original sound recording and needs a Master License.)
- Arrangement - The arrangement or structure of a song is not something we copyright either. Just like rhythms, song structures are used across all genres. Think what would happen if you tried claim infringement because someone's song was AABA (a.k.a. the 32 Bar Form). You can have two songs with the same structure, but they would sound completely different. (The only exception to this is when you've created a unique arrangement to a song and added original melodic composition or lyrics. In that case it becomes a derivate work, which is copyrightable but needs permission from the original rights holders first.)
- Protected Parts (Unique Works)
Exceptions to the Rules
Since anyone can claim infringement in a court of law, we see exceptions to the rules above from time to time. This article from Buzzfeed breaks down part of the legal process when someone claims ownership of musical elements that are not typically protected. Since we are not lawyers, we always recommend visiting Copyright.gov for the most up-to-date Copyright Law information.