(NOTE: This method is not wi-fi safe. Anyone you connect with will hear no music playing when you use one of your added tracks while playing with them, and you can be reported and banned for it. If you're playing with friends in Battle Arenas, you're fine, but playing with random people is a big risk.)
What you'll need:
1. The Sm5shMusic program, created by . https://github.com/Deinonychus71/Sm5shMusic/releases
2. The files Smash Ultimate uses to track music details. These files are:
- msg_bgm+[insert your region here].msbt (ex: the US region file is called msg_bgm+us_en.msbt)
- msg_title+[insert your region here].msbt (see above)
3. nus3audio files of the songs you want to add. You can find most of them easily on http://smashcustommusic.net , but if you want to add a song that's not listed there, you'll have to create the file yourself. There are tutorials on how to do that on GameBanana, so consult those first.
Now that you have everything you need, it's time to get down to brass tacks.
Step 1. Preparing the program for usage
First off, take the folder provided in the download of this tutorial and drag/drop all of its contents into the "Resources" folder of Sm5shMusic. Sm5shMusic will not run unless it detects all of the proper files in this folder, so make sure to do that first.
When you first open up the program, it will look a little something like this. In order to start using it, you must first click "Manage...", and then click "Create a mod". This will create a folder that all the songs you are adding will go to, which Sm5shMusic will read in order to properly add the tracks to the necessary files.
When you click "Create a Mod", you will get a popup window that looks like this. You can type whatever you want as the mod name, and Sm5shMusic will automatically name the folder for you. Once you have your mod folder created, that's where the fun begins.
Step 2. Adding songs to Sm5shMusic
Once you have your mod folder created, you can click the "Import Songs to..." tab, and click the name of the mod you just created. At this point, Sm5shMusic will pop up another window that allows you to explore your files and add the nus3audio files you've prepared to the program. The name of the nus3audio files doesn't matter, you can name them whatever you see fit.
Once you've added all the files you want to add, this screen will pop up for every file you just added, so you can tell Sm5shMusic the specifics about the song.
The "tone id" box is the name of the nus3audio file, and is automatically filled in for you.
The "Game" box is for the name of the game this particular song comes from. If you're adding a song from a game that is not already covered by Ultimate (as I have done here with a Persona 5 Royal song), you can click "Create New Game", which will take you to a pop up window that looks like this:
Type the name of the game this song comes from in the top box, and the "Game ID" box will be automatically filled out for you based on what you wrote in the top box.
The "Series" dropdown is so you can tell Sm5shMusic what series this game comes from. Sm5shMusic will not let you progress with adding a new game unless you tell it the series, so make sure to do that.
Now, back to the song itself. Once you have the game prepared, type its name into the proper box, and Sm5shMusic will handle the "Series" box for you.
The "Record Type" box is you telling Sm5shMusic if this song is a remix or not. An easy way to think about it is setting the box to "Remix" will have the song display a little blue triangle in the corner of its name in-game, "New Remix" will have it display a little red triangle, and "Original" will have no triangle whatsoever.
Next is the middle section. "Title" is self-explanatory; it's the name of the song itself. "Author" is who composed/wrote the song, and "Copyright" is who owns the song.
"Author" and "Copyright" are not necessary to fill out, but are nice to add just to make the song fit in better with all the other songs, aesthetically.
You may notice that the middle boxes have dropdown boxes that say "English (US)" and "Copy..." on them.
The first box is the region these details will be added to; mine is currently set to "English (US)", which means the title, author, and copyright of this song will display if Ultimate is set to the US region.
"Copy..." allows you to copy these details to other regions, if the appropriate msg_bgm and msg_title are present in the "Resources" folder of Sm5shMusic.
If you're making this mod only for yourself, you can safely ignore these options, as you only need to set up the mod for your own region. If you plan to share this mod with others, setting the mod up so that all regions are covered is advised.
Finally, the righthand set of options. "Volume" is also self-explanatory; it's how loud the song will be in-game. The default volume for all tracks is 2.7, and the current maximum is 20. If you test out the mod and find some songs are too quiet or too loud, mess around with this slider a bit.
"Sound Test" determines if this song will show up in the Sound Test, or if it will only display when you're choosing the music for the stage you added the song too. I recommend just keeping this box checked, but it's up to you.
"Special Category" is for 2 specific things. The first is "Pinch Songs", which are songs like the Street Fighter tracks, in which the music changes when someone is down to their last stock and/or a timed match reaches the end of the timer. When you set a song to be a pinch song, another category will pop up asking you what song you want the current song to change to when the time is right. This can be any song, whether it be a base game song or a song currently in your mod.
The second is "Persona 3/4/5 Stage" which determines what form Mementos will take if this song were to play on that stage. For example, if you set a song to have the "Persona 3 Stage" special category, that song would turn Mementos blue if you played it on Mementos.
As mentioned, this pop up will occur for every song you've added, so once you've completed filling it out for every song, you can move into step 3.
Step 3. Adding the songs to the proper playlists
Once you've got all your ducks in a row, your Sm5shMusic program will start lookin' a little bit like this. While you're on this screen, you can edit the info of tracks if you notice you made a mistake, or delete them from the mod if you decide you don't want them anymore.
From here, you'll want to click on the "Playlists" tab in the upper right, which will take you to a screen that looks like this:
On the left is all the songs you've added to the program. The righthand box is where the playlists will be displayed once you choose the one you want to edit. To choose a playlist, click the "Select a playlist..." button above the righthand box.
You'll get a dropdown menu that looks like this. From here, just click on the series you want to edit, and its playlist will display in the righthand box.
Like so. From here, you can drag and drop songs from the lefthand box to the righthand one. Songs will display in-game in the order you placed them in this program, so if you're an orderly sort, make sure you keep track of what songs you're placing where.
If you decide you don't want a song on the playlist you just added it to, click the "X" on the righthand side to remove that song from the playlist. (NOTE: if you delete a song in this menu, it only deletes it from the playlist, not from the game itself. If you want to delete an added song from the game, do it in the previous menu.)
The sliders you see next to each song is the "Incidence" of the song; basically how likely the song is to play on the stage if you set the music to random. By default, all added songs are set to 0 incidence, because the game doesn't have preset values for it. But you can edit the incidence both in this program and in-game with no issues whatsoever.
Once you're satisfied with your playlists, it's time to actually build the mod itself.
Step 4. Building the mod
Once you're ready to actually build the mod you've created and put it to use, click "Project" in the top left of Sm5shMusic.
"Build" will build the mod and remember how the songs were set up in playlists so you can easily re-edit the mod later, at the cost of adding more files that Sm5shMusic has to remember.
"Build (no cache)" will build the mod WITHOUT remembering how the songs were set up, meaning you'll have to set the playlists up again if you decide to edit the mod. If the "Build" option gives you an error, building with no cache will usually fix it.
Once you click one of the build options, the program will handle all the back-end work for you, and will spit out all the relevant mod files in a folder called "ArcOutput". (NOTE: If you already have an "ArcOutput" folder from building a previous mod, Sm5shMusic will tell you it has to delete the previous folder before it can build the new mod. This is fine, so just say yes when it asks you.)
From there, all you need to do is drag and drop the contents of the "ArcOutput" folder into your SD card like you would if you were installing any other mod, and you're done! (NOTE: Drag and drop the CONTENTS of the "ArcOutput" folder, not the "ArcOutput" folder itself.)
Step 5 (OPTIONAL): Creating a custom series
As of the most recent update to Sm5shMusic, you can now create custom series that you can categorize your songs into, and these custom series will show up on the Sound Test and when selecting music for Battlefield/Final Destination.
First, click on "Create a Series" in the "Manage..." drop down menu.
The menu here is self-explanatory. Just enter the name of the new series you want to add to the game, and then click "Create". From then on, any time you have to choose what series a new game you're adding to Smash is from, this custom series will be listed in the options.
If you'd like to move a game you've already created to a custom series, click "Edit a Game" in the "Manage..." menu.
A screen will pop up that looks like this. Just type the name of the game you want to edit into the box, and then a screen similar to this will pop up.
Click the "Series" drop-down menu, and select the custom series you just created. Then click "Save Changes", and you're good. Now all songs that are assigned to that game will appear within the custom series playlist.
NOTE: Custom series will not appear in the Battlefield/Final Destination music selection menu unless the songs within that series are assigned to a playlist. Make sure to assign all your songs to a playlist before building your mod.
Step 5.5 (OPTIONAL): Creating a custom series icon
Detailing this step in the GameBanana post would add too much text to an already text-heavy tutorial, so please go to the Google Doc link for this part of the tutorial.
Step 6 (OPTIONAL): Creating a custom playlist
If you'd like a certain stage to have its own playlist, made entirely of songs you decide that stage to have, you also have the option of creating your own playlist that you can assign on a stage-by-stage basis, as opposed to the playlist being based on series.
In the "Playlists" tab of Sm5shMusic, click "Manage..." and then "Create a Playlist".
You'll get a pop-up that looks like this. Name the playlist whatever you see fit, and then hit "Create". Then find your playlist in the drop-down list of all the others, and add whatever songs you see fit to it.
Once your playlist is ready, click "Manage..." again, and then "Assign a stage to playlist".
A window that looks like this will pop up. Choose the stage you want to change the playlist for in the first box, and then in the second box, scroll through until you find your own playlist. The "Playlist Order ID" is essentially a way for the game to randomize your playlist using a set order, but it's fine to just leave it at "Order 0", which will default to the order you already set the playlist up in.
Click "Save Changes", and then build the mod as you would normally.
Download for "Resources" folder: https://www.dropbox.com/s/0joxrdlrb18gcgs/Resources.zip?dl=0