Any video intended for the web needs to be accompanied by good audio work, but between the hawks of copyright and YouTube's disastrous automatic system, the most likely outcome is silence. The best way to avoid this is to use sounds with flexible licenses, and that leads us to the Sample Focus portal, where we can download a large number of samples for direct use, or combine them into new melodies.
There are quite a few people who currently criticize the "magic of the space bar". By that I mean a whole new generation of artists dedicated to electronic music, who seem to be very good at mixing, but not so much when composing. This debate has been going on for many years, and with an ever-increasing reliance on technology to create music, it will probably never end. Meanwhile, while professionals try to resolve that "problem," let's think about those users who want to prepare their own mixes, place them in a video, and upload that content to portals like YouTube. Where do they get the samples from?
Free sounds for your multimedia creations
Taking a piece of audio from a movie or a song is inviting disaster, because the electronic ears of the "Great Supercopyright" listen 24 hours a day, and as if that weren't enough, YouTube's automatic system has caused headaches for tens of thousands of users. The solution is to obtain samples with a permissive license (that is, it may carry some natural restrictions, while allowing personal use without inconvenience), and so we arrive at the territory of Sample Focus.
Laser shots? Explosions? Weapons? Screams? A classic piano? Sample Focus has it all. All we have to do to hear each sample is place the mouse cursor over it, but the site places great emphasis on metadata, so a simple keyword leads to dozens of samples distributed across various collections.
To download the sounds we must create an account on Sample Focus (or as a shortcut, use Facebook credentials), and in each entry you can study the details of the licenses. From what I've been able to verify, the vast majority of restrictions focus on the redistribution of the samples. While there are no problems with their use in music, movies, advertisements, and games, what they don't want is for them to be downloaded from another place, or resold as a pack.