To jam and learn the simple chords for Jean-Pax Méfret - Jour J chords, practice playing C, F, C, F, Bb, A, D, G, D, Bm and D in sequence. A strategic approach would be to train at 49 BPM initially, and then accelerate to the song's tempo of 99. Fine-tune the capo based on your vocal range, ensuring it complements the key of D Major.