Yes; materials in the public domain do not require any licenses.
The website Petrucci Music Library contains a lot of public domain (free) sheet music. It has about 337 sheet music titles for Ludwig van beethoven. You could also try JustSheetMusic which also contains alot of free/public domain sheet music for beethoven.
This music, by Beethoven, is in the public domain. See the link below:
There is a great deal of public domain sheet music available at the links below.
There is a public domain site that has lots of his music. See the link below:
If the music is in the public domain, you can find it legally on the internet. Otherwise you have to buy the sheet music. Artists deserve payment. Sometimes public libraries will buy sheet music so you can check if yours does.
The website Wikipedia carries lists of public domain music, and there are more specialist sites such as choral wiki which carry certain types of music, for example sheet piano music.
It will be difficult to find free sheet music for popular music, because most of it will be copyrighted... music is copyrighted until the composer has been dead for 100 years. After the composer has been dead for 100 years, the music is then considered to be in the public domain, which means it can then be used for free. So, music like Christmas carols or church hymns is in the public domain. However, if someone makes an arrangement of a public domain piece of music, that arrangement is now considered copyrighted by the arranger, and that arrangement is not in the public domain until the arranger has been dead for 100 years.
Legally you can get it at public domain sites or from its right-holders if they choose to offer it free of charge.
International music score library project - public domain. The link is in the 'Related Links' section below.
if it is a well-known classical gavotte like Gossec's "Gavotte in D", it is in the Public Domain, and you can download it from one of the PD sheet music sites free.
Free legal sheet music can be found at public domain websites or at platforms where composers offer it for free directly to performers. Check the links below.
An extensive list of songs in the public domain (in the US) is linked below. It's much harder to find public domain recordings, as the copyrights for sound recordings are especially convoluted.