Software that lowers the pitch without slowing down. Generally, recording software has this function.

COOL EDIT can be easily achieved. It can be lowered within three tones, which will not cause great damage to the file. If it is lowered too much, it will be mixed.

COOL EDIT download website:

After installation, open the software, insert music, double-click to enter the single track, click on the effects tab, select pitch change or speed change - change speed, enter the pitch change dialog box, pull down to raise or lower In the key window, #1, #2, etc. are one key up or two keys up. b1, b2, etc. are one or two tones down.

Very simple!