I’m sure you have noticed that Cape Breton fiddlers, and the majority of traditional musicians of all genres tap their foot somehow when they play. This is a natural response to the music they are playing. However, when you are a learner of traditional music and from a different background like the classical musical tradition, tapping the foot might not seem so natural.
It may not seem important but tapping your foot to the music that you are playing and feeling it in this way may actually improve your playing- at least the rhythmic aspect. It can even help nail down melodies more solidly. I’ve seen this improvement with many of my students, sometimes almost instantly. Tapping the foot helps you understand what notes fall on the beat. This is particularly helpful if you are having trouble with keeping time. When my students understand the melody in relation to the beat, they tend to remember the melody better. The beat becomes a reference point and changes perception of the melody when it may not make sense.
Strathspeys tend to be particulariy tricky rhythmically for those who are not used to hearing them. Tapping the foot becomes especially important when learning this tune type since the rhythms are so complex with dotted 8th notes and 16ths as well as 16th note passages and triplets. For example, if in a strathspey you have a run of four groups of triplets, it can be easy to make them sound like a big blob of notes rather then 4 distinct groups of triplets if the first note of each group is not emphasized. Tapping your foot on the start of each triplet will helps solidify where the beat is in this run and the natural emphasis will most likely come through in your playing.
Don’t worry if you initially have trouble coordinating your foot while playing. It may take a while to feel natural. Start with small phrases. For example, if it is a passage of four groups of triplets that you are working on, make sure that first you understand which note your foot will fall on. Then maybe start by coordinating your foot to the first two groups of triplets, then try adding the next one, then the next until you can tap your foot to each beat of the passage.
Once you get the feel for this, you will experience playing tunes in a completely different way.