I want to start recording music on my Mac system and am stuck at sample rate and channels. For reference purposes, can I pick an audio file and see what its sample rate is and how many channels have been utilized for the recording?
Congrats on deciding to record your own music. There’s never enough music in the world, so adding more is a good thing, and you’ve picked a good system by starting out on a Macintosh. Lots of great software, not the least of which is the free Garage Band, which a surprising number of professional musicians are already using for sampling, arrangements and recordings themselves.
Knowing sampling rates and channels can be helpful in terms of what you want to output, but I have to say that most everything I’ve encountered is either mono or 2-channel stereo, recorded at 44.1kHz. Notice I say “2-channel stereo” because few people realize that “stereo” allows for more than two channels in its encoding. Heck, back in the 1940’s inventor Marvin Camras was demonstrating three channel — left, right, center — “stereophonic” recordings.
Yeah, 2 channels. 44,100 sample rate. But don’t believe me, let’s have a look! To demonstrate I’ll tap the music I’m listening to as I write this article, the Spectre motion picture soundtrack by Thomas Newman.
In iTunes, it looks like this:
Move the cursor over the track name and a button with three dots shows up.
Click on it and a menu of choices appears:
Interesting options but not what we seek.
Instead — and this is an insider trick! — Control-Click on the specific track you want to learn more about…
Ah, there’s what you want. Choose “Show in Finder” to proceed, and you’ll see the track in the Finder, along with the rest of the album (Spectre Original Motion Picture Soundtrack, in this case):
Select the track in question, then press Command-I or choose Get Info from the File menu.
Either way, you’ll get more information about the track in question:
Interesting information but not what you seek.
Don’t despair, though! Instead, click on “More Info:” just below the General pane of information.
And in this segment you’ll get the exact information you seek:
There we go. Now you can see that the sample rate for Snow Plane, the 11th track on “Spectre (Original Motion Picture Soundtrack)” is 44,100 and that it is comprised of 2 audio channels and has a total track duration of 5:24.
As a side note for the geeky readers, you can also ascertain this from the command line on a Mac system using the cool mdls command, like this:
kMDItemAudioChannelCount = 2
kMDItemAudioSampleRate = 44100
So now you know, for what value that might have! 🙂