Firstly, a quick disclaimer:
I am not a copyright lawyer and as such this is intended as a general guide
only, it is a brief overview of copyright legislation which is an enormously complex field with many exceptions and details which are impossible to cover here.
This article is not intended to constitute legal advice and should not be relied on as such.
Now that that is out of the way,
Do I need a license to use this music?
The answer is almost cerrtainly yes, all music is covered by copyright automatically as soon as it is written down/recorded and these rights belong to the composer (jointly if there is more than one or composer and lyricist etc.)
Anything that you produce for public viewing, regardless of whether it is for profit or not and regardless of whether you are a student (with a few small and very limited exceptions) that includes the music of someone else needs there permission in the form of a synchronisation license.
When you are using music there are actually two aspects to consider
How long does Copyright last?
The copyright in the musical work itself.
The copyright in the recording.
These are two seperate things and you need to ensure that you are covered on both counts, for example Beethoven is out of copyright however you cannot simply grab a CD from the shelf and use the music because there is still a copyright interest in the recording.
When will The Work (not the recording) be out of copyright (public domain)
In 1986 The Berne Convention for the Protection of Literary and Artistic works established a degree of uniformity around copyright
law as almost every country has signed up to it.
The duration of copyright is based on a period of time after the creator (whether they be author, composer, photographer etc.) died plus a set period of time (life +__)
The Berne Convention sets a minimum term of copyright of at least life+ 50 years (except for photographic work which is life+25 years), however many countries have gone for a longer term including all members of the European Union and the US who have a copyright term of life+70 years, with a few exceptions which I have mentioned below
If you wish to be able to show your product around the world then this is the best figure to work from however, if you are creating something for a specific location you can check the length of copyright in various countries here.
Isn’t 1922 the cut off date?
Many people will tell you that 1922 is the magic date before which everything is out of copyright it is important to note that this is only the case in the United States.
The US had complex copyright laws before signing the Berne convention but between 1923 – 1978 copyright lasted for 95 years from publication and from 1978 it is life+70 years.
For countries other than the US use Life+70years.
There are a lot of small exceptions and oddities surrounding copyright law so if the work you wish to use is from around these dates I would strongly suggest you seek legal advice but they are a very good ballpark.
When will The Recording be out of copyright?
The length of the copyright in the recording is different from that in the work.
The European Union has only recently (last year) decided to extend the duration of copyright in recordings however this has yet to be introduced to law so currently protection is for 50 years from the date the recording was made however in the United States I’m afraid things are a little more complex.
The United States introduced The Copyright Act of 1976 which ensured that all recordings made on or after the 15th February 1972 were covered by the standard copyright term I mentioned above, unfortunately recordings made before that date are still (and will be up until 2047) covered by state law which can be different from state to state.
Complex as all this your safest bet is to go for the life+70years calculation which means that almost any usable recording will still be in copyright in the US but if you are working in Europe you can use recordings from before 1961, but only if the author/composer died more than 70 years ago so that there is no longer any copyright in the work.