Original Song,Song Length,
Preludefmajor,0:38,
preludegmajor,0:56,
kinderszenenamcamin,1:00,
Cancun,1:01,
kinderszenenbittendeskind,1:10,
flightofthebumblebees,1:26,
Leyenda,1:31,
symphonyno6_mvmt1st,1:37,
Danceofthehours,1:47,
Preludeeminor,1:48,
Friendlylandscape,1:56,
Preludeno1incmajor,2:06,
Symphonyno3adagio,2:08,
Dedicatoria,2:15,
Gnossieneno3,2:19,
Walzinamajor,2:22,
Wodiezitronenbluehn,2:25,
Aquarium,2:29,
Clairedelune,2:32,
symphonyno6_mvmt4th,2:33,
Peergyntmountainking,2:35,
Scherzopolka,2:49,
symphonyno5_mvmt2nd,2:58,
Hungariandanceno1,2:59,
kinderszenentraumeri,3:04,
Symphonyno7_mvmt2nd,3:05,
Louisaspolka,3:08,
Berceuse,3:09,
Preludealapresmididunfaune,3:15,
tannhauseroverture,3:16,
Symphonyno9newworld,3:17,
Nightonbaremountain,3:17,
Bacarolle,3:21,
Arabesque,3:24,
Mars,3:27,
Anitrasdance,3:29,
Preludeineminor,3:32,
Minuet,3:38,
Waltzfantasy,3:49,
Sicilienne,3:52,
Dererlkoenig,3:53,
Concertoflautodolce,4:06,
Themoldau,4:17,
Inthemonastery,4:19,
Aironthegstring,4:27,
Solvejgssong,4:49,
Cataluna,4:51,
Reverie,4:52,
rideofthevalkyries,5:19,
Slavonicdance2,5:31,
Granada,5:31,
Symphonyno3_mvmt3rd,6:27,
Pavaneinfsharpminor,6:31,
Larlesienneoverture,6:37,
Onthesteppesofcentralasia,6:56,
Venus,7:10,
Symphonyno7_mvmt1st,8:00,
Symphonyno2_mvmt3rd,8:35,
Orpheussymphonic,11:55,

 
Used tools: Archive2, Audacity, XWM Music Converter and Excel.
 
I started by reverse-engineering another successful FO76 radio mod, More Where That Came From, by opening its .bsa2 file using Archive2. This showed me that a radio mod simply contains .xwm audio files. When the .bsa2 is loaded, those .xwm files are replaced, much like a simple retexture mod. A .xwm file is a specific audio file type used in Bethesda games that you can easily convert to from a .wav. That bit of reverse-engineering showed me everything I needed to do to create my own radio mod.
 
I used Bethesda's Archive2 tool (get this by downloading the FO4 creation kit) to open the Sounds01.bsa2 file (located in FO76/Data), and exported the .xmv files for all the Classical radio songs. This was about 59 .xmv songs.
 
Then, I converted those .xwm files into .wav using a converter tool. I used XWM Music Converter.
 
I then started an Excel worksheet to keep track of the lengths of all the original .wav files (as well as function columns here which track time / 2, time / 3, to help find lengths that would fit 2 or 3 songs in), and a second sheet to track all the lengths of the prospective songs I wanted to add. A third sheet tracked which prospective songs I could fit into the time lengths of the originals.
 
I collected a large quantity of songs and ads, 116 total, as you won't be able to use every song you want. Think of what you're doing as 'filling air time', you need to fill specific time lengths with new songs. I also gave them each a rating, and notes regarding possible trimming times or why I applied that rating. Ratings and notes helped me make tough decisions when it came time to choose my favourites for particular time slots. I began to assign prospective songs to the original time lengths in my Excel sheet.
 
For instance, the original 7-minute Classical radio song 'Venus' was assigned a 30-second Blue Coal ad, as well as the 3:22 song That Old Black Magic, and 3:08 Pagan Love Song.
 
One important part of this is that while assigning songs to the originals, you need to keep in mind that you will not often be able to match the song lengths exactly. You'll likely end up with a few short seconds of air time. At the other extreme, you cannot just put a 2:00 song in the place of a 4:00 original and expect it to work well, what will happen is an extra 2:00 of empty air. If you go over the original time, you'll cause overlapping audio, although most records have a couple seconds before they begin so a small amount is OK. You'll need to cram more than one song in the time length of certain original tracks, sometimes up to 4 songs to fill an especially long song.

I worked my way through all the original Classical radio tracks, filling the largest and smallest tracks first in my Excel sheet, since I reasoned doing the extremes first would give me an easier time with the final few median times.
 
The above is the largest part of the project. Collecting audio, rating it, and finding time slots is the main part of a radio mod project, and happens in Excel. The other main part of the work is in Audacity.
 
Once I was happy with my song overwrite assignments in Excel, I opened Audacity and worked on the original tracks one-by-one. I muted the original Classical music, and imported my custom songs over it to match the lengths according to my Excel sheet. I also reduced the audio volume to match the level of the original songs. I made commercials just a bit quieter. I exported it with the same name as the original track, but with different audio. So, for instance, I would export a file named 'mus_radio_76_classical_antonbruckner_symphonyno7_mvmt2nd' but the contents would actually be the song 'A Hundred Years from Today'.
 
Once I had exported each of the original audio files, which I replaced with custom audio but kept the original names, I then converted them from .wav back into .xwv format. Then, I pack that back into a .bsa2 archive, and voila! A custom radio mod that will replace the original music!

I had a small issue at the end with the folder path. It is important that Classical radio stations have a /classical path, and not a /general like the Appalachia radio.