Why introduce a metronome into the middle of that. It's annoying little click is extraneous to the music and a hindrance to knowing it's rhythm. It seems to spoil the whole idea!
I agree 100%. The Zen/Buddhist concept of "mindfulness", though, is a good one. Practicing an instrument is a form of meditation, without a doubt. By playing a composer's music, by focusing and mining the score for the composer's intentions, one can leave one's own self behind--"lose attachment"--and that is a good thing. There are pitfalls in seeking mindfulness, however. Rather than trying to be mindful while practicing: just practice. Rather than using the metronome: keep time. Rather than thinking about breathing: breathe. Muho Noelke, the abbot of Antaiji, explains the pitfalls of consciously seeking mindfulness:"We have to forget things like "I should be mindful of this or that." If you are mindful, you are already creating a separation ("I - am - mindful - of - ...."). Don't be mindful, please! When you walk, just walk. Let the walk walk. Let the talk talk (Dogen Zenji says: "When we open our mouths, it is filled with Dharma"). Let the eating eat, the sitting sit, the work work. Let sleep sleep."Let the pianist play piano.