You need to install an application for this trick. Download Here
After installing Pocket File Manager, follow the below mentioned steps.
1. Open the Pocket File Manager app and browse to the Pictures folder ( from SD card or Phone storage depending on where you save photos ). On the Pictures folder, you will see a couple of sub folders named Camera Roll, Screenshots, Saved Pictures etc. Make a new folder there. Let’s name it “WhatsApp Audio”
2. Now using the Pocket File Manager app, copy the songs or music or audio file on your phone. For example, if I want to send music via WhatsApp, I would go to Music folder ( on SD card or Phone storage depending on where I save new music by default ) and from the folder of artist, I long press over the song to pop the option to copy the song.
3. Head back to the new “WhatsApp Audio” folder in the Pictures folder we created in the first step. Paste the song there.
4. Now long press over the song you just pasted on “WhatsApp Audio” to pop the options and select rename operation from it.For audio files, the file extensions are usually .mp3 or .wma . Rename the file extension of the song you copied to .mp4
5.Now open WhatsApp and when adding attachment, select Albums. Choose the Albums, you will see the “WhatsApp Audio” folder there. Tap on it to open the folder. You will see the song which we copied and renamed the extension there.
6.Send it. Don’t worry about the changed file extension of the music file. The receiver on the other end should be receiving the file as .mp3 file ( even though we send it as .mp4 file).
