1. Use the right foot most of the time. Although there are times when it is possible to keep the left foot on the swell pedal, it is the right foot which can be most conveniently used in manipulating it. In fact, some organs (especially from the 19th century) have the pedal placed in the far right side of the pedalboard.
2. Plan your pedaling. Right in your pedaling with the swell pedal in mind. If you see any signs of crescendo or diminuendo in the score, this indicates the places for the swell pedal. This means that you should leave the left foot for playing the pedal part in such episodes. However, it is possible to engage the swell pedal and to play with the right foot in the same fragment. You will only need to be very quick with your movements.
3. Make the foot movement very gradual. The best use of the swell pedal is when the listener doesn't perceive it as such. If you could make the movement of your foot very gradual, your dynamics will sound quite natural. Otherwise the listeners will hear a lot of sound waves which would make your piece sound exaggerated.
4. Practice repeatedly in small fragments. The best way to learn to use the swell pedal is to take a short fragment (preferably long enough for one crescendo or diminuendo) and play in a very slow tempo many times. Treat swell pedal mistakes seriously and correct them right away.
5. Sometimes you will need an assistant. There are places in some pieces where the organist is required to use the swell pedal but both feet are busy with the pedal part. For example, this can happen when you play double octaves or when the pedal part is truly virtuosic with too many leaps. These are the places for an extra help from an assistant.
6. Don't use it for early music. Since the swell pedal was invented in the 19th century, we don't normally use it in the Renaissance or Baroque music. However, feel free to adjust the dynamics before the piece starts. This might be quite necessary for a good balance between the parts.
Apply the above tips when you practice and play pieces composed in 19th century and later. Be mindful of the preparation and adjustment time required so plan accordingly. Don't take the swell pedal for granted. You must practice repeatedly applying it in your organ music.
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