[Noan1999]

Good night.

By chance someone knows to extract and insert the NSF to a NES ROM.

It is that I need to modify the music to an EarthBound Zero ROM.

[Jorpho]

NSFs do not work that way.  See for instance https://www.romhacking.net/forum/index.php?topic=30083.0 .

If you want to change the music in Earthbound Zero, you will have to determine how the music is stored in the ROM, and then find some way to convert the music you want into that format. 

This is not at all easy to do – unless someone out there has done it already.

(Alternatively, you can find some way to remove its music engine entirely and replace it with new code, but that is obviously not easier.)

[Noan1999]

NSFs do not work that way.  See for instance https://www.romhacking.net/forum/index.php?topic=30083.0 .

If you want to change the music in Earthbound Zero, you will have to determine how the music is stored in the ROM, and then find some way to convert the music you want into that format. 

This is not at all easy to do – unless someone out there has done it already.

(Alternatively, you can find some way to remove its music engine entirely and replace it with new code, but that is obviously not easier.)

OK, I got it...

I already know where the music data is in the EarthBound Zero ROM (According to the ROM Map).

I thought that the NSF files were extracted from a NES ROM. Because I extracted the music data to create a NSF. I tried to reproduce it in an emulator but it didn't work.

What I want is to modify the music without changing the music engine (I mean to use the EarthBound Zero Original engine).

[sebastianangel]

If you mean to modify the same music of the game while maintaining the engine, it is relatively easier, you can do it with the FCEUX emulator and use code / data / recorder and look for the music data that are in a blue color in hexadecimal and play with them until you find the modification or variant that you like best in the ROM