When did Pink Floyd acquire or secure copyright for the songs, becoming Dark Side Of The Moon?

[Mark45]

At the very start of 1972, Pink Floyd began performing the embryonic version of DSOTM.

Assume that another band heard any of these shows (Best of Tour 1972 came out shortly after the Rainbow shows) and decided to record them in the studio, and release them on vinyl. Would this have been a legal, or an illegal action?

Had Pink Floyd already secured 'all' rights by performing the songs live, or would that have required official/formal registration first?

[Paul]

That is a good question, especially in todays world, that has more of an opportunity, with more opportunists to make it happen. I know back in the day if you mailed, through the post office, your self a copy of your performance you were good, that would be considered your copyright until such time you went about doing it the right way.

[MrFender]

Under contract law, there is something known as the "mailbox" or "postal" rule that states an offer or contract is accepted when it was sent back (dropped in the mailbox) from the offeree to the offeror. Not sure that would apply to this type of situation but one would think it would be fairly easy to contest someone else stealing it by showing PF wrote and performed it first as an original work of art either through depositions of attendees/management/band members or even bootleg recordings.

Does anyone know the formal filing process?

[goldenband]

At the very start of 1972, Pink Floyd began performing the embryonic version of DSOTM.

Assume that another band heard any of these shows (Best of Tour 1972 came out shortly after the Rainbow shows) and decided to record them in the studio, and release them on vinyl. Would this have been a legal, or an illegal action?

Illegal, unless given permission by the band. You can record and release a cover of someone else's work without permission once they've released their own authorized version, because that fulfills the condition for a "compulsory license" that allows anyone to record it as long as they play royalties and don't change the basic character of the work.

But until it's been published with the copyright holder's authorization (bootlegs don't count), you can't release your own cover version unless you get permission from them. One reason for this is exactly what you describe: a composer or songwriter shouldn't be "beaten to the punch" by someone who goes to a show, learns their songs, and steals their thunder by releasing the first recording of their songs.

This is all based on my limited understanding of US law in 2023; other jurisdictions and time periods will no doubt vary.