Thursday, April 7, 2016

Families of Orchestra Instruments in the MIDI Hymn Project

One of the goals of the MIDI Hymn Project is to learn about the instruments of the orchestra and how to use them to voice a hymn.  The simplest of the techniques is answering the question, "Which voice (soprano, alto, tenor, bass) can this instrument play?"  As a class we explored two simple ways of knowing which instruments could play the voices of a hymn: (1) what is the size of the instrument and (2) what range of notes does it play?

How to find the range of an instrument in Wikipedia

Sizes of musical instruments have a direct impact on how high or low a note it can play.  As a general rule, the smaller the instrument (like a piccolo), the higher it can play.  Likewise, the bigger and longer the instrument, the lower it can play (like a double bass).  What does a particular instrument sound like? Look it up in Youtube by searching for the the instrument and the word "solo" to hear that instrument by itself, like this for "English horn solo".

There are four families of instruments in the orchestra: string, woodwind, brass, and percussion.

In a hymn, there are usually four voices: Soprano, Alto, Tenor, and Bass.

In Garageband, pitch designations are assigned with numbers: 0 means "as written", +12 means and octave higher (literally, 12 half steps), and -12 means an octave lower.  To make octave adjustments, open up the track editor by either clicking on a green region or the track editor button, which looks like a scissors.
Track Editor Button
How to make octave adjustments in Garageband 10.1.0

In the string family, I used the following instruments, voices, and pitch designations:
  • Violin 1, playing the soprano part at +12, an octave above the written melody to help the melody stand out.
  • Violin 2,  playing the soprano part at 0 
  • Viola, playing the alto part, at 0
  • Cello, playing the tenor part, at 0
  • Cello, playing the bass part, at 0
  • Double Bass, playing the bass part at -12, doubling the cellos at the lower octave
String Family
In the woodwind family, I used the following instruments, voices, and pitch designations:
  • Piccolo, playing the soprano part at +12, an octave above the written melody to help the melody stand out.
  • Flute,  playing the soprano part at +12, an octave above...
  • Oboe, playing the soprano part at 0
  • Clarinet,  playing the alto part at 0
  • English Horn, playing the tenor part at 0
  • Bassoon, playing the bass part, at 0
  • Bassoon, playing the bass part at -12, doubling the other bassoons at the lower octave
Woodwind Family
When we listened to the woodwind family by itself, the oboe was sticking out of the mix too loudly. We pulled back on the track volume of the oboe to help it fit back into the mix better.



In the brass family, I used the following instruments, voices, and pitch designations:
  • Trumpets,  playing the soprano part at 0 
  • French Horn, playing the alto part, at 0
  • Trombones, playing the tenor part, at 0
  • Trombones, playing the bass part, at 0
  • Tuba, playing the bass part at -12, doubling the trombones at the lower octave.

Brass Family

Finally, we panned the sound in Garageband so it would sound like it was coming from where the instrument in the orchestra was sitting.  How do you pan sound?  Every track has a pan knob.

Pan knobs in Garageband 10.1.0
Pan knobs let you direct the sound coming from Garageband to either the left or the right ear of your headphones.  Drag the pan knob up or down to turn it.  Then, imagine that you are the conductor of the orchestra and point the pan knob in the direction of where the instrument sits in the orchestra. Do this for all of the instruments in a family to spread them from left to right across the stereo spectrum of your headphones.



I haven't said a thing about how to enter notes in Garageband (I wrote how to do that in April 2014) , why I have four piano tracks in my project, or why we added percussion to hymns.  We first entered the notes of Glory Be to Jesus in four piano tracks, one track for each of the voices of the hymn. Why enter the music into four tracks and not all into one?  In order to have many different instruments playing the soprano part, it has to exist by itself in a track–it cannot have other voices with it.  I left the piano tracks in my final orchestra mix because the piano helps define the attack at the beginning of a note.  Some instruments (strings, woodwinds) have a very slow attack and feel behind the beat.

This year, I decided to have my students add percussion to their MIDI hymn projects because (a) percussion is an instrumental family of the orchestra, and (2) percussion makes the hymn come alive and propels the beat and the energy of the hymn forward.  The simplest way to add percussion is to drag in a loop of a beat from the loop menu.  We also added drum fills at the ends of verses to teach how a drummer changes the pattern at the end of a pattern to alert the listener that a new part of music is coming up.

Here's what my version of "Glory Be to Jesus" sounds like using the symphony orchestra jam pack from Garageband.


Monday, February 8, 2016

Audio File Formats

Wav, mp3, aif, aac, mp4... What are they? What's the difference between them?

Most people don't have to think about this topic, let alone these questions, but electronic musicians have to think about audio file formats every time they rip a CD to their hard drive, sync their iPod or phone, or play streaming audio over the internet. I'll explain each one of these file formats separately under three categories: "Uncompressed", "Lossless" and "Lossy".


These two audio formats are what you would use if you want to preserve the highest quality of a digital recording. Neither one of these two formats compresses the audio in any way, but the tradeoff is a big file size: 9-10x bigger than and mp3 file size of the same song!

AIFF – short for Audio Interchange File Format (.aif), developed by Apple in 1988

WAV – short for Waveform Audio (.wav), developed by Microsoft in 1992.


Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange for better compression rates.  Lossless compression also applies to digital images.

Apple Lossless - (.m4a) introduced by Apple Corporation in 1994.  What's the difference between AAC and M4A? Read this article.


Lossy compression is a data compression method which yields small file sizes, but from which the original data can never be totally reconstructed. Lossy compression will always results in generation loss: repeatedly compressing and decompressing a file will cause it to progressively lose quality. Lossy compression also applies to digital images.

MP3 - short for Motion Pictures Expert Group (MPEG-1) Audio Layer 3, developed in 1995

AAC - stands for Advanced Audio Coding
Pros: Designed to fix "serious performance flaws" in the MP3 format
Cons: some would view it as a proprietary format, only useable on iPods, iPhones, and other Apple Computer software, such as iTunes, but AAC files are compatible with Creative Zen Portable, Microsoft Zune, Sony PlayStation Portable (PSP), other portable media players, and mobile phones

WMA - stands for Windows Media Audio, developed by Microsoft in 1999


Tuesday, January 5, 2016

Three-Chord Guitar Songs

The final unit of Music Tech class is decidedly "non techy": it's learning how to play the guitar. Why? Many years ago the final unit was a songwriting unit using Garageband.  The students were encouraged to make their own song in Garageband using the loops that were provided.  The problem was that students stacked loops on top of each other that had conflicting chords.  How do I teach my students to hear chords? By teaching them to play chords on an acoustic guitar!

The goal of the guitar unit is to be able to play a simple three-chord song, even though during the course of the unit the students have learned five chords: G, C, D7, A7 and Em.  It reminds me of a (somewhat) famous Youtube sensation, Axis of Awesome's 4 Chord Song.  The idea is that if you know four basic chords: I, vi, IV, V (in G: G, Em, C, D) then you can play almost a thousand songs.

How many songs can you play with only three chords? Many, many, many!!



What three-chord song can you learn? Go search for "three chord songs" on Google or look through these three chord song lists for ideas:

Song Lists:

10 Famous Songs with Three Chords or Less via Guitartricks.com