What is a triad? An interval? A unison? A chord? An extended chord?
A chord is made up of three or more notes played together or as an arpeggio (playing the notes of a chord in a specific pattern). The C Major chord has the notes C, E, and G, but can contain the same notes played as an inversion - upside down. For example, a C major chord could contain three occurrences of the notes C, G, and E: C, E, G is root position, E, G, C is first inversion, and G, C, E is second inverion. In general, the notes of the chord come from the notes of its scale.
An interval is the difference between two notes and is one of the building blocks of music. An interval is most often thought of (and measured) in steps and half steps. For example, the distance (interval) between the notes D and E is one step, whereas the interval between D and D# is one half step. Intervals have names such as a melodic minor second (one half step — one piano key next to another) or a melodic major second (one whole step — two piano keys separated by the one key between them). Other names include minor sixth, major seventh and perfect fifth. Two notes in unison have an interval of zero (they are the same note) whereas an octave is separate by twelve keys on the piano.
A triad is simply three notes played together (though not always readily identified as a chord). Triads are based on a particular scale and are named as minor or major (as well as augmented or diminished). As an example, here are the triads based on a C scale: C,E,G – D,F,A – E,G,B – F,A,C – G,B,D – A,C,E – and B,D,E.
The word unison means that each player is playing the exact same melody or series of notes. In a choir for example, everyone would sing the same part. In almost every case, unison also means that all the players or singers are following the same rules in regard to style and dynamics. It’s important to remember that although (singing or playing) an octave sounds very much like a unison, it is not. Using unison in a piece of music often gives the music strength (volume) and emphasis. It also is a great way to define a particular passage or phrase.
An extended chord contains notes of a chord that are extended (added) beyond an octave. Examples of extended chords are ninth, eleventh, and thirteenth chords. In the case of the ninth chord, the ninth note of the chord’s scale is added to the chord. For example, a C ninth chord contains the note D. Examples of extended chords are ninth, eleventh, thirteenth chords. Using a C chord as an example, the C 9th chord contains the notes C, E, G, Bb and D. Beyond this, it also means that certain notes of extended chords need not be played for the chord to continue to “function” as intended.
A suspended (or suspended fourth chord), contains the fourth note of the chord’s scale. For example, the fourth note of the C scale is F. So a C major suspended chord contains the notes C, E, F, and G. Suspended chords are normally used temporarily and sparingly but add a dimension of suspense to music.
Posts Tagged ‘interval’
What is a triad? An interval? A unison? A chord? An extended chord?
Thursday, April 9th, 2009Changing Keys In a Song: What is transposition, and how can I do it?
Wednesday, August 27th, 2008
Transposition is changing the key of a piece of music, or changing the notes without changing their relationship. This is often done to make the piece of music easier to play or sing. It’s a common practice in bands that don’t perform their own material; the singer may wish to cover a song with vocals that are far out of his or her range. Transposition can correct that problem by shifting the key into a range that is comfortable for him or her. Transposition is also used with instruments. Some instruments (called transposing instruments) are not tuned to the same note; for instance, a Bb clarinet is tuned to a B flat and an alto clarinet to an E flat. Transposition of the sheet music for these instruments ensures that they won’t sound discordant when playing with the rest of the orchestra or band.
Transposition may be a simple concept, but it take lots of practice to achieve. The easiest sort of transposition — and technically it is not transposition at all, since it remains in the same key - is done by octave — simply moving the piece of music up or down eight steps. This sort of transposition may work for a male singer wishing to sing a female’s part, but it does little for transposing instruments or other areas of vocal work. In these cases, it’s best to use transposition by either scale degree or harmonic interval.
Transposition by scale degree uses the scale degrees of a piece of music to determine the relationship between the notes. Each note in a piece is assigned a scale degree (tonic, dominant, subdominant, mediant, submediant, etc.) and the same scale degrees are used for the new key. This type of transposition is potentially simple, as the relationship between the notes will always remain the same, regardless of the key.
Transposition by harmonic interval uses intervals as a guide for the transposition. By finding the interval between the dominant notes in the two keys, one can deduce the interval between the all the notes. If the difference between the notes is a major third, then transposition of all the notes will be done by a major third. This type of transposition is also potentially simple but calls for an added carefulness when dealing with accidentals that aren’t expressed in the key signature.
The very best way to transpose is to learn to think in more than one key. Most beginners start learning in the key of C, so after awhile they can think in that key — they know where the notes in that key are, and their fingers can get to them easily. Since every key a person can play in is mathematically the same as every other key, by learning to play in a 2nd key one can learn to think in that key, just as they did in the key of C.
Keys are like languages: if you don’t know Spanish, you certainly can’t think in Spanish, and when you learn to speak it, you will have to rack your brain for the right word for quite awhile before you begin to think in Spanish. Its the same in music — there are only 12 major keys in which you can play (in contract to languages, where there are hundreds) — so if you can eventually learn to think in all those 12 major keys, there is no key left that you couldn’t transpose in to.
Practically speaking, however, most people don’t need to know all 12 keys — just the keys in which most songs are written: C, F, G, D, A, Bb, and Eb. If you can learn the other six too, that’s fabulous, but you can certainly get by with just those 6 keys, or perhaps even less — and least C, F, and G — the “big 3” when it comes to keys.
To learn more about transposing, go to How To Transpose & Modulate
and How To Think In The Key
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