The starting point for deciding the issue of ownership comes from the traditional idea that copyright exists “before the ink is dry on the page”. This means the initial copyright belongs to the author of the work. The main exception to this is where the author was an employee and the work was created in the course of employment, in which case the owner is the employer.
Where the work has been commissioned the ownership still initially belongs to the author, not the person commissioning the work. However, most agreements for commissioned work contain a clause to transfer ownership to the person doing the commissioning. Indeed, the courts are likely to find that such a clause implied even when not explicitly stated. If they did not do this, it would be possible to prevent the commissioner from using the work they paid for.
A sound recording belongs to the producer and a film belongs to the principle director.
To demonstrate the complications of ownership, consider the example of a band releasing an album:
The ownership of the individual songs depends on the input given by each member of the band. Possibly only one band member owns a song, or they may be joint owners, or it may be that one person owns the music and another owns the lyrics. This could be different for each song. It maybe that the band assigned all the copyright ownership to the record company in its contract with them.
The sound recordings would belong to the album producer, or the company that employs them.
The album cover would belong to the artist or photographer who created it (or their employer). This is different if they assigned the ownership to another through a contract (perhaps because they were commissioned to create the work).