Japa is the most portable practice in Hinduism and the one most likely to be happening on a bus. The mala has 108 beads plus a head bead, and you do not cross the head bead — you reverse, which is why the practice has a shape rather than a loop. The count of 108 has a dozen explanations, astronomical and arithmetical, none of them authoritative. Practice ranges from muttering to silent mental repetition, which the texts rank highest, and the mantra is normally received from a teacher and kept private. The Gaudiya tradition made the count explicit and public: sixteen rounds a day is a vow taken at initiation, roughly two hours of chanting, recorded in a book. In the nirguna bhakti stream, Kabir and Nanak both attacked bead-counting as theatre while keeping the repetition of the name as the practice, which is a distinction worth noticing.