Tuesday, August 25, 2015

Egads! I just found out why some of my shows SOUND SO HORRIBLE!

Because it is so difficult to get WXPI 88.5 off the air, we have to connect our stereo to one of our phones, or a computer, and get it off the Internet.  About 30% of the time, the broadcast sounded terrible; there was a lot of rumble and distortion in the signal, and I was beginning to suspect that TuneIn Radio (which hosts the Internet feed) was sabotaging my program, for reasons unknown.

Then, for various reasons, I found out how to access the Station's radio archives.  (Radio stations are either required to maintain archives, or choose to maintain archives, I don't know which.)  I was actually trying to locate an old program by somebody else, when I became curious and hunted down one of my own Saturday night broadcasts, and---OMG!!  It really was terrible.

Then I pulled the thing into Audacity (which is audio-editing software, and almost the only way you can trim the archive file to exactly a single broadcast), and looked at the segment of my show that was in one of the files; about a whole hour of it, station breaks and all.  And I saw that it had been compressed.

A word about compression.

As you know, the volume of a program varies naturally from moment to moment; when I'm talking, for instance, the volume between one word and the next is almost zero.  In contrast, the volume of a piece of music is never zero, but also varies with the volume of the music.  Here are some examples:
If further explanation is necessary: in this example, both left and right channels have roughly the same volume throughout.  Observe how the spoken part has lots of silences, especially at the end, before the music starts.  Some of the very soft sounds are just me breathing, if you can believe that.

Now, I'm going to compress this clip.  This is where the software amplifies the soft parts, and softens the loud parts.  This makes the contrast between loud and soft a little less, so that the music will be audible inside a car, but not too loud (so you can concentrate on driving instead of the volume control).  The resulting signal looks like this:

Observe that, in comparison with the original sound clip, the "soft" parts are not as soft, and the "loud" parts are just about as loud as before.  This is a tricky transformation; the program must, at each point in the clip, calculate the "average" volume for the fraction of a second around that point, and juice up (or juice down) the clip for that moment, and go on to the next.  To really see the effect of compression, you have to look at both the images and compare.

Now, when I manually compress my program, I leave my introduction alone.  But it appears that if the sound file is too soft, in the judgment of the Station program (SAM), it compresses the entire file.  This means that even the soft sounds of a breath I take is amplified, until it sounds as if I'm having an Asthma attack.  Similarly, the very soft sounds of the music in the quiet passages are amplified, and we hear the rumble of passing trucks near the studio where the recording might have been made.  This is a lesson for us: compression must be undertaken judiciously, and not left to the studio computer.

In my desperate attempts to avoid distortion, I was actually making the perceived distortion worse.  So last week, I made each file as loud as possible.  This made the program SAM believe that the file was nice and loud, and needed no compression.

I continue to do my own compression, because some passages are so incredibly soft, you have to wonder what the recording engineers are thinking.  These files played over a weak radio transmitter will almost disappear entirely.  But now I know that I have to save all my sound files at maximum volume, and everything will be fine.

Sunday, August 16, 2015

Show 206: Form and Structure of Larger Musical Works

This was an abbreviated show of about an hour, but the topic is important, even if we did not go into it in great depth.

Writing a short piece of music is not hard: you think up a tune, polish it up a little, put in some harmony, and you’re done.  When you want to write a major piece of music (I don’t mean to suggest that you listeners want to do this, but it helps to look at the problem from the point of view of the composer) structure raises it’s —not necessarily ugly— head.


Monday, August 3, 2015

Show 205: Slow Movements

a Pas de deux is typically danced to a slow movement
Back in the old days when we older folks used to listen to cassette players, I would make lovely 2-hour cassettes of my favorite cuts from the LP's that I owned, and put them in a little portable cassette player —the predecessor of boom boxes, which in turn are the predecessors of mp3 players— and listen to the music on headphones.

The first really carefully-planned cassette mixes I made were of the middle slow movements of a variety of major works that I liked.  This worked beautifully for when I was studying in a library, to keep me calm and focused.  (I didn’t need fast, energetic music to keep me awake, because I was really into whatever I was working on; the music was more to cover the distracting sounds of undergraduates carrying on about something totally silly, from my exalted grad student point of view.)  Since last week we listened to the high-energy finales from major works, I thought this week we’ll listen to the soothing sounds of slow movements.

Many of my friends, whom I have forced to listen to Archie’s Archives, have cracked up when there is a transition from something slow and serious to something quite unrelated.  Such moments were frequent in the earlier broadcasts; I would follow a romantic duet from a serious opera with Steve Martin and Bernadette Peters singing Tonight you belong to me.  It seemed perfectly logical to me, but not to everybody else.  At least on this next show, it will all be slow movements, or mostly slow movements!  In classical works, like symphonies and sonatas, these slow movements were a contrasting, lyrical interlude between more dramatic outer movements.

Sunday, August 2, 2015

Show 204: Grand Finales

The theme for this week is those jolly and rousing send-offs that end multi-movement works.  Here's the spoken introduction we put on the air to begin the show:

Part A  (Bach, Schutz, Dylan)

Introduction
Hello, Welcome to Archie’s Archives on WXPI 88.5.  I’m Archie, and this weekly program introduces listeners to classical music.

As I have said before, there is a lot of different kinds of classical music, and since I’m only a volunteer, and like all WXPI show hosts, do this because I like classical music, you’re going to hear mostly the sort of music that I like, unless I specifically try to play something that I don’t like, or I happen to play something that I didn’t listen to first, and so I haven’t got an opinion about it one way or the other!

You probably know by now that I write music in a small way.  I’ve already played a couple of pieces I wrote.  The piece that I wrote first is a chorale-prelude, which means that it took as its springboard another piece, in this case a chorale by Johann Cruger.  I’ll play that for you sometime.  (Actually, it's right here, if you just can't wait to hear it.)

All these pieces I wrote are very short, less than 5 minutes long, most of them.  It’s when you begin writing extended pieces, long works —full scale musical pieces like symphonies are called works, if they can be plausibly published all by themselves— you run up against the problem: how to write a long work?  That’s a discussion we should get into sometime, and look at various solutions composers have adopted.  But the earliest solution is to write a multi-movement work.

These sorts of multi-movement works usually have a nice, upbeat ending, which is usually called the Finale.  (I looked up the pronunciation of this word, and the British pronunciation is fi-na'-le, and the American pronunciation is fi-nal'-li.  It is an Italian word, so it probably ought to be pronounced fi-NAH-leh.  Like Machchi-AH-to, or Prosci-OOT-Toh.  Anyway, these last movements are a lot of fun to listen to, so that’s going to be the featured sort of movement I play for you today.  And, as always, it’s going to be my favorite finales, so don’t be sore.  If you would like to hear your favorite finales, you have two options, at least.
[1] write to me, archiewxpi@gmail.com, and tell me what you would like to hear.  If I think it fits in with one of our program themes in the next few weeks, it will be there.  If it is really interesting, theme or no theme, I’ll put it in anyway, if I can find it.
[2] You can always sign up as a show host for WXPI — just contact Curt Musheno at station@wxpiradio.org
You can call your show: Pieces Archie Refuses to Play, or something like that!
Hélène Grimaud

The theme music today is being played by Hélène Grimaud, who is a lovely lady, and I must put up a picture of her on our website.  Our website could do with a few nice pictures on there, I have to admit.  I must not be sexist, but in this post-PC world that we are slowly entering, I should hope that Mlle Grimaud does not take exception to being characterized as a beauty.  Let me say, in case you misunderstand, that she is being featured because she is arguably one of the two people who play this piece the best; the other being Mr. Alexis Weissenberg, whose performance I put in our podcast for last week.  I took out Mr. Miecszyslaw Horzowski’s performance, because I thought Mr. Weissenberg does a better job.  (So, obviously, the pieces on the podcast are often just a little different from the pieces on the radio broadcast.)