YouTube tutorial video here: http://www.youtube.com/watch?v=di4nOopPF2M

Introduction
Have you ever wanted your battle music to play the beginning once, and then loop the main part only, like most Final Fantasy music?
That's exactly what this tutorial will teach you how to do.

Required Program
You need to download the free audio editing tool, Audacity 1.3 Beta from here. I'm pretty sure the 1.2 version will not work.

Editing the BGM
Open your desired BGM in Audacity. Find the portion that you want to loop by using the selection tool and zoom tool and carefully listening to where the song should begin looping, and where the song should restart to the beginning of the loop. These two points in the song MUST sound exactly the same! It is recommended that the loop point is loud, because trying to loop on a quiet, sensitive part of a song is more noticeable and harder to make it seamless.

Once you know where the points are, select the point where the loop should begin, and then go to Tracks -> Add Label at Selection. Enter "Loop Start." Do the same for where you want the loop to restart, and label it as "Loop End."

You can test to see if it loops seamlessly by highlighting the area inside these two labels and shift+clicking the play button.


Next, thou shall go to the bottom of the program, where you shall see some drop-down menus. Click a drop-down menu and set it to "samples" like shown in this image:


and then make sure that "Length" is checked instead of "End" like so:


Now, make sure that you have selected the area of the song from the Loop Start label to the Loop End label, and then go to File -> Export...
Name it, and make sure the File Type is set to Ogg Vorbis Files. Click Save.

This is the most important step! An Edit Metadata window should appear. At the bottom, click add until there are two blank tags. Double click the first blank tag and type in "LOOPSTART". In the second blank tag, type in "LOOPLENGTH". Look at the bottom of Audacity to see a number under Selection Start. Insert this number as the value for LOOPSTART without commas. Do the same for LOOPLENGTH using the number under Length.


Click OK, import your new ogg file inside your RPG Maker VX, go to Sound Test, and click Play!
If it loops exactly where you wanted it to, then you have not failed.

Go forth, and make awesomeness.

Brilliant thanks for the submission, don't forget your youtube link can also be displayed within your post by using the youtube tags.

I can see this being put to good use, and this will loop constantly?

Yup, it loops the specified part forever. =)
I thought about attaching the youtube directly but since the details are quite small, a fullscreen view is recommended anyway, haha.

Excellent tutorial that clearly explains how to do this.

Quick question, though. Can any file (Midi, MP3, ogg) be played and looped following this, as long as it is renamed as an ogg file?

Or does audacity only support a certain kind of file to ogg format?

I would assume it has something to do with how the ogg reader is written in the engine which can read these custom loop points.
Otherwise you should be able to insert loop points for other music formats and it should work without renaming to ogg (that is, if an ogg reader tried to read a midi file it'd probably crash)

Audacity is a very, very powerful audio editing tool that can read most audio files already, so as long as you open the audio file, be it WAV, MP3, OGG or whatever, and export it as an Ogg, you should be fine.

As for midi files, I know that Audacity can import them, but I have not messed around with it too much, so I am not sure. I know that midi files have their own method of determining where the loop starts, because this is what it says in the help file:
"MIDI files played via the DirectMusic Synthesizer. If a BGM MIDI file contains the control change value 111, that value is recognized as where the song will start repeating after it reaches the end."

This is a great tutorial and I am sure it will be handy for many people. Thanks for spending the time to do it.
Also, since the topic only mentioned VX I was curious if it would work with the XP as well and tried it. Sadly, it does not. So even if this is basically is useless for me, VX users will put this to good use I suppose ^^

Thanks a lot this worked like a charm ^^
Credits for you

I did all the steps, but when I play it on the Sound test, it doesn't loop. I check on it again and the loopend tag is there and the loopstart is gone!

It should work if you do exactly what the tuto says and it loops in vx not outside of it i think

Also, make sure the two values are LOOPSTART and LOOPLENGTH, not LOOPEND.

Very good tutorial! I didn't know Audacity had features like that. For how much Logic Pro (what I use) is used for video game music, you'd be surprised that there's no feature like that in that program.

Extra Note: When working on the music you want to loop, if you have control over the reverb bus for that song, you're going to want to keep it to a minimum for looping. It might not sound as flashy, but it just loops a lot more smoothly.