Moving iTunes 12.x Library to iTunes 2.0.4, Part 2: Converting AAC to MP3

Moving iTunes 12.x Library

In my earlier post on moving a modern iTunes 12.x library back to iTunes 2.0.4 (on Mac OS 9.2.2), I noted that a key issue I encountered in that process was that iTunes 2.0.4 supported only the MP3 format, and that none of my AAC (M4A) formatted music was able to make the transition from the modern iTunes 12.x to the vintage iTunes 2.0.4. Since this significantly limited what I could download to my first generation iPod (about half my iTunes library is AAC formatted), I set out to solve this problem.

My key requirement was batch processing. I had to be able to point the solution at my entire iTunes library, and have it find and process all the M4A files there into MP3 files in a single GUI or command line step, vs. album by album, which would have been prohibitively difficult from a time and personal patience perspective. I was not averse to an album-by-album approach if it was command line based and I could script it, achieving a single script operation, but in one way or the other, the conversion had to occur in an automatic way, searching out all M4A files and converting them to MP3 with no intervention on my behalf.

Many readers will shudder at the words “command line based”, but yes, I am old enough, and geeky enough, to be fully versed in command line usage, having long experience with DOS initially, and then with various flavors of Unix and finally with various flavors of Linux, all of which set me up beautifully to use the Mac OS X Terminal command line.


I investigated numerous AAC to MP3 tools, including various forms of Sox (both command line and GUI based), the excellent Audacity program, and some wonderfully multi-threated general purpose conversion tools, one or two of which could indeed be scripted.

Then the lights came on in my mind and I realized that I had had the answer under my nose all along: iTunes! I recalled seeing a “Create MP3 Version” context command in iTunes, available by right clicking any given tune. If iTunes could convert a single tune, then perhaps it could convert an entire collection of tunes. Regrettably, whenever I right clicked a tune in the iTunes 9.2.1 on my Tiger-based Power Mac G5, the only “convert” option I got was to create an AAC (M4A) version – not exactly the MP3 option I was looking for!

Create MP3 Version, 02

Playing with iTunes preferences, I quickly realized that the convert option was context sensitive. If, in the Import Settings preferences, the AAC (M4A) encoder was selected, the per tune right click convert option was to convert to M4A. If, however, the MP3 encoder was selected in the Import Settings, that same convert option then changed to “Create MP3 Version”!

MP3 Encoder

All I had to do now was to get iTunes to bulk convert all of the M4A tunes to MP3 format in this way. This turned out to be fairly easy. In the iTunes View options (available from the main iTunes menu bar), placing iTunes into “List” view showed all of the tunes in a list, vs. all of the albums in a grid. Next I added a column to the list view for “Kind”, which showed the “kind” of encoding for each tune, either MP3 or AAC.

View As List

Finally, I clicked on the Kind header to sort all of the list view tunes into “kind” order. Now I had a list of all my tunes, with the AAC-encoded tunes all grouped together at the top, followed by all the MP3-encoded tunes, and then finally a small number of other kinds as well, such as M4P, WAV and so on.

I then selected the complete set of AAC-encoded tunes and right clicked the whole selection. “Create MP3 Version” appeared in the resulting context menu, and I selected it. Off it went. An hour or so later it was done, and all of my M4A tunes now had an MP3 counterpart.

Create MP3 Version

As a test, I did this twice, once on my 2.5 GHz Power Mac G5 Quad and again on my 2.3 GHz Power Mac G5 Dual, just to see if the G5 Quad would outperform the G5 Dual at this CPU intensive task. Regrettably, the iTunes 9.2.1 conversion code does not appear to be multi-threaded, and so the operation took close to the same amount of time on each machine. In round numbers, it took about a minute per album, with each album comprised of on average ten songs. Doing the math, this is about six seconds per song.

If you are using a faster or a slower machine, your results will vary accordingly. The amount of RAM didn’t seem to have much of an impact, so you needn’t worry about more or less RAM being a factor. My Power Mac G5 Quad is equipped with 8 GB of RAM while my Power Mac G5 Dual has only 2.5 GB of RAM installed. Despite the large difference in the amount of RAM, the conversion took about the same time on both machines.

I was a little worried about CPU loading while this operation was underway, and so I kept a close eye on my iStat Pro widget during the process to ensure that the CPUs were not getting overly warm. In both cases (G5 Quad and G5 Dual), the CPUs did not exceed about 62 C, which is in the safe operating zone for G5s. Given that, I was content that this task was not placing an undo strain on them. Start worrying about a G5 if it exceeds 70 C for an extended period of time.

iStatPro During MP3 Conversion

So, without further ado, here is the complete “recipe” for using iTunes 9.2.1 to convert AAC (M4A) files to MP3 files:

  • Go to iTunes Preferences, Import Settings, and select the MP3 encoder
  • Go to the iTunes View menu, and set iTunes to List view
  • If it is not already present, add a column to List view for “Kind”
  • Use this column to sort your music list into AAC, MP3 and other kinds
  • Select all of your AAC tunes
  • Right click and select “Create MP3 Version”
  • Sit back, relax and enjoy your flight… OOPS! Yes, my job DOES have me traveling by air too much these days! ☺ What I meant was, sit back, relax and wait for iTunes to complete the conversion.

Your augmented iTunes library is now ready to be transferred to iTunes 2.0.4 (or any other MP3-only music program)!

One final note. My music collection consists largely of CDs that I have ripped, and I keep it in its own folder hierarchy, completely separate from the iTunes folder hierarchy. As I rip each album, I tell iTunes to import the result, but not to copy the file into the iTunes library. Hence my iTunes folder itself is quite small, consisting only of several iTunes database files, but no music files.

This worked to my favor during the MP3 conversion. While iTunes was happy to create the MP3 versions for me, it offered me no control whatsoever over where it put the results! So, once the conversion was done, in order to transfer the newly converted MP3s to my Mac OS 9.2.2 / iTunes 2.0.4 system, I had to find them first! If iTunes had interspersed them amongst the originals in my music folder hierarchy, I would have had to write a script to copy them all out into a single spot so that I could transfer them over.

Happily, iTunes had done no such thing. Instead, it had stuck them all into the “iTunes Music” subfolder of the main iTunes folder. Since these were the only actual music files in the iTunes folder, they were easy to find, and were all together in one place. It was, therefore, a simple task to copy that entire folder onto a memory stick and then onto my Mac OS 9.2.2 system. iTunes 2.0.4 was then more than happy to import the results and I finally had a more or less complete copy of my current iTunes 12.x library in iTunes 2.0.4! If you ever decide to load your current iTunes library onto iTunes 2.0.4, you may wish to keep this in the back of your mind. A music library kept outside of the main iTunes folder will make your life a little easier.

So, that is it, and completes the saga of transferring a modern iTunes 12.x library to Mac OS 9.2.2 and iTunes 2.0.4. If you should ever be so curious as to try such a thing yourself, I hope that these two posts may be of some assistance.

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