In past WebRhythm lessons, we've dealt primarily with pure rhythm - note values, counting systems and such. This lesson will take a little detour to learn about one of the notational oddities that can occur in the world of reading percussion music: rhythmic abbreviations.
In a way, these abbreviations are very similar to contractions or acronyms in the English language. Words like "can't", "I'm", or "she'll" are popular in contemporary language because they are quicker to say and write than their complete counterparts. Likewise, acronyms such as ASCAP or PASIC are springing up all over the place because it just takes too long to write or say "American Society of Composers, Authors and Publishers".
With rhythmic abbreviations, certain rhythms can be written quicker, but remember that no time is saved during a performance - each note still gets its full time value regardless of how abbreviated its script. Take a look at example 1. Both measures in this example indicate the same rhythm. In the first measure, you see a series of sixteen sixteenth notes. The second measure shows one of the abbreviations that can be used in place of the sixteen different notes.
As you can see, writing all those sixteenth notes would take sixteen motions of your pencil or pen (or mouse clicks for that matter), the stems would add another sixteen strokes, and the beams would add eight more movements. The abbreviated version uses only two noteheads, two stems, and four slashes. Obviously, there can be no argument that eight movements are more efficient than forty.
Why would two half notes with two slashes through their stems indicate a full measure of sixteenths? The slashes are the abbreviated symbols for note values with beams.
An analogy can be made between rhythmic abbreviations and penny candy. I remember riding my bike to a small drug store near my home. With twenty to thirty cents in my pocket, I could really put myself into a sugar coma. I'd tell the guy behind the counter that I wanted six cents worth of these, three cents worth of those, or ten cents worth of whatever.
The amount of candy that I could buy was related to two factors -- first, the price of each type of candy and second, the amount of money I wanted to spend on that particular goodie. If I bought ten cents worth of candy that sold for a penny each, then I ended up with ten pieces of candy. If I bought ten cents worth of candy that sold for two pennies each, I ended up with only five pieces of candy.
So, what does penny candy have to do with rhythmic abbreviations? Slashes through a note's stem are abbreviated beams. In the second measure of the first example, the two slashes indicate the type of note that has two beams (sixteenths). The fact that the slashes are through the half note's stem means that the composer is asking for "a half note's worth of sixteenths". And everyone knows that eight sixteenths equal the value of a half note. Put two of these figures next to each other and presto - a full bar of sixteenths!
In example 2, the half note's stem has a single slash. Since each slash is an abbreviation for a beam, the composer is asking you to perform "a half note's worth of eighths" (the note value that has one beam). Because eighth notes are longer than sixteenths, there will be only four eighths in the time of the half note (like more expensive candy).
The second measure of this example shows four quarter notes. The first two quarters have a single slash - indicating eighth notes. The last two quarters have two slashes - indicating sixteenth notes. For the first two counts, each figure represents a quarter's worth of eighths. The last two figures represent a quarter's worth of sixteenths. If you're checking yourself for the proper interpretation, the first two measures of the example should sound exactly like the last two bars.
Generally speaking, abbreviations are easy to perform. You simply fill up the abbreviated note's amount of time with the rhythmic values specified by the number of slashes through the stem. But things can get a little more complicated if the abbreviated note is already beamed.
In example 3, the very first figure has a single slash through the stem that should indicate eighth notes. But the abbreviated note is itself an eighth note! What gives?! Earlier, I stated that slashes through a stem are abbreviated beams, but it would be a mistake to say that a single slash always means eighth notes. In the example, the eighth note already has one beam, so the slash serves as an abbreviation for the second beam - sixteenth notes. In other words, each eighth note with a slash should be interpreted as "an eighth note's worth of sixteenths" (two sixteenths). As before, you can check yourself by comparing the last two bars of the example with the first two bars. They are simply the same two measures written without the abbreviations.
Example 4 carries this process a little further by adding a slash to sixteenth notes. Again, since the slash is an abbreviation for a beam, and sixteenth notes already have two beams, the composer is asking for "a sixteenth note's worth of thirty-seconds."
One last possibility for confusion: standard percussion notation uses abbreviated thirty-second notes to indicate a roll. If you run into something like example 5, you need to decide if the composer is asking for a roll that lasts the value of a half note or a half note's value of thirty-second notes. Since the title of this series is "WebRhythms" instead of WebRolls, assume abbreviations for now.