Scratch

Scratch projects, including all their assets, are distributed under a Creative Commons Attribution-Share Alike license. This means that you may use anything actually created by another Scratcher, if you give credit, and share your project (Scratch or not) under the same license. See here.

However, assets copyrighted to other people, which you could download in a Scratch project (ej. a videogame's sprites, some band's music), will still be under the copyright. If a Scratch user is accused of violating copyright laws, the Scratch website "will take appropriate actions under the Digital Millennium Copyright Act (“DMCA”) and other applicable intellectual property laws", as said here.

tl;dr:

Using sounds created by another Scratcher, which are part of a project = Not illegal at all.
Using copyrighted music found in a project = The copyright older may take (possibly legal) action against you. Not illegal under Fair Use.

technoguyx wrote:

Scratch projects, including all their assets, are distributed under a Creative Commons Attribution-Share Alike license. This means that you may use anything actually created by another Scratcher, if you give credit, and share your project (Scratch or not) under the same license.

However, assets copyrighted to other people, which you could download in a Scratch project (ej. a videogame's sprites, some band's music), will still be under the copyright. If a Scratch user is accused of violating copyright laws, the Scratch website "will take appropriate actions under the Digital Millennium Copyright Act (“DMCA”) and other applicable intellectual property laws"

tl;dr:

Using sounds created by another Scratcher, which are part of a project = Not illegal at all.
Using copyrighted music found in a project = The copyright older may take (possibly legal) action against you. Not illegal under

It would be minecraft sounds(eg walking, braking blocks) no music though. is it ok?