The marimba sets that are becoming more and more central to school music programmes are mostly diatonic. This means, of course, that they have limited key possibilities. But they are certainly not limited musically. It’s worth thinking about what you gain and what you lose when instruments are limited to a few diatonic scales and the full chromatic scale is not an option.
Western classical music takes harmony seriously. The underlying logic is linear, because the music follows the logic of its harmonic progression, in other words, how one chord follows another. Music can stay in one key, using chords built only from the notes of one scale, or it can modulate – travel into another key and use a new set of chords. The music I am thinking about here is on a large scale – like symphonic music. This music takes you off on a harmonic journey where the twists and turns, climaxes and surprises are mostly achieved through harmonic progressions, keys and chords. The techniques and tricks developed over centuries in Western classical music, and Western opera especially, are the ones that are still used today in film music (and TV, Radio and podcasts) to evoke certain feelings. They can bring surprise, or suspense, or the warm feeling of a couple falling in love. These have been around for such a long time that we learn them subliminally just by our exposure to media. So – back to Western classical music – What counts is harmony. Rhythm tends to take a lesser role. Even where a Western composer’s music is rhythmically complex, take Stravinsky for example, it still doesn’t come close to the rhythmic complexity of West African drum ensembles. The main interest (and complexity) is in the harmony.
African music has a far more limited harmonic palette. This is also true of music with African roots like the blues and today’s popular music. It’s always dangerous to make sweeping generalisations, but while there is an enormous range of tuned traditional African instruments, most often they don’t play music beyond a few scales or modes. The Chopi Xylophone pictured here has a 7 note scale. Some have a mere 4 notes in the scale, many have 5 note scales, others 6 or 7 note scales. Crucially, it’s not linear harmonic journeys, but cyclic ones that give traditional African music one of its most powerful tools. Sometimes this involves a single chord, often it’s 2 chords that move back and forth in regular or shifting patterns. The four chord structures of South African struggle anthems are reminiscent of the blues insofar as they are powerfully generative. The unchanging chord structure provides a foundation for all sorts of other stuff to happen. And the most important place this happens is in the rhythm.
A pared down harmonic dimension makes space for rhythm to take centre stage. Combine cycling chords and rhythmic variety and you get groove. Many African instruments are essentially percussive, no matter whether they are blown, or plucked, scraped or struck. This percussive quality adds to the rhythmic identity of each instrument and its music.
Marimbas have a lovely double inheritance that draws on African xylophones, Western tonality and choral part singing. Most commonly, marimbas in Southern Africa are in C Major, but have an added F#, giving the potential for music in 2 Major keys, and their related minors and modes. Of course, some marimbas have removeable notes (so you can exchange a C natural for a C #, etc.), and some makers produce a chromatic section that fits behind the diatonic keyboard to give a fully chromatic scale. But it seems to me that the excitement of marimbas and what they can do is completely achievable without the chromatic notes. There are several reasons for this. First, marimbas are energising because they’re percussive and because great marimba music makes the most of interesting and contrasting rhythms that work together to create the vibe. When each player has their own unique part, and it links beautifully with the other parts, learners develop the skill of playing together and when they do it well, it is enormous fun. Also, fewer notes in the scale makes it much easier to remember which notes to play. Without those chromatic notes, there are fewer notes to confuse inexperienced players. That is not to say that marimbas won’t stretch young musicians. Remember the West African drumming example? There is plenty of potential to challenge players as they develop their marimba skills, as Marimba Jam’s 8 level syllabus for marimba shows.
So, what do you lose when you don’t have a chromatic scale? First, Bach’s 48 are out. Seriously though, when you want to arrange a particular number, you might well have an ‘If only I had a B Flat’ moment. For musicians used to 12 tones, your brain might need to do some shifts. Modulation is limited too. But we’re thinking about Western priorities here, and when you consider what you will win with a diatonic marimba, it’s a no brainer. The wins are: Simpler keyboards, faster learning, focus on rhythm, students really playing together and learning to groove, and huge fun.