There are many applications that merges mp3 files but an easy way to do it without any application is doing it by Cmd. by merging I mean that if you have two or more mp3 files, after merging them it will become one mp3 file that contains both of them.

To do so follow these 3 Steps :

Step 1 :- Create a New Folder and copy the mp3 files you want to merge inside it. It is better to number the mp3 files in order you want them to be merged, for example if you have two mp3 fils by the name "First song.mp3" and "Second song.mp3", it is good to rename them with "1-first song.mp3" and "2-Second song.mp3" or just rename them with 1.mp3 and 2.mp3. (the first song to be played will be 1.mp3 and the second will be 2.mp3 in the merged file).

Step 2 :- Open Cmd and go to the directory of the folder where your files are, or simply Hold Shift key and right click on the the folder and from the menu select Open command window here  and then enter the below command in cmd and press enter :

in here I named "mergedsong" the new mp3 file, but you can give any name you want.

Stpe 3:- Now you can see the magic. If you open the folder again, you will see a new file named "mergedsong.mp3" which is a mix file of your two mp3s .