Contact the copyright holder and request permission.
Thus, material must be original and published in a concrete medium of expression to be covered by a copyright. In other words, for material to be eligible for copyright protection, a tangible product must exist
You must either contact them or if possible, flag what they have copied.
The material must be of sufficient originality, and fixed in a tangible medium.
No. One of the great "urban myths" is that "if it's on the net it must be free". Nothing modern and creative is in the public domain (meaning it's free to use without permission) anymore unless the owner explicitly puts it in the public domain (explicitly as IN WRITING). Assume that 99.999% of the time anything you see on the internet is protected by copyright and if you want to use it, ask permission.
I think that getting the/a copyright to Star Trek is basically impossible, considering that that copyright must be owned by the movie companies and people who created it or their beneficiaries/heirs.
There Must Be Somebody Else was created in 1927.
Usually, your agreement with the copyright holder will specify a notification (such as "used by permission") which must appear on or with the work.
The specific wording varies from country to country, but in general the work must have some amound of originality and creativity, and it must be fixed in a tangible medium. Fixing doesn't necessarily requre a material form, though: digital works are also considered to be fixed.
Perry Como
In most countries copyright is free, instantaneous and automatic.
copyright library
Yes somebody will still own it - depending on your jurisdiction a play or musical remains in copyright for the life of the author + a number of years. In Europe it is life + 70 years. As Jule Styne only died within the last 10 years it must still be in copyright. This applies even if the author sells or assigns the rights to somebody else. The rights are listed as owend by Wonderful Music Corp - but I had heard a little rumour that Barbra Streisand bought them some time ago but I don't know if this is true or not.