Slametan is the Javanese communal meal and tahlilan the recitation for the dead, and together they are the connective tissue of Indonesian Islam — the largest Muslim population on earth. Neighbours gather on mats, a kiai or an elder leads the tahlil, and then everyone eats from a shared cone of rice and takes a portion home. The occasions are life's hinges: a birth, the seventh month of pregnancy, a house move, a circumcision, and above all the deaths — the third, seventh, fortieth, hundredth and thousandth day after. Nahdlatul Ulama, founded in 1926 and with tens of millions of members rooted in the pesantren boarding schools, defends these practices as legitimate local expression, part of what its scholars call Islam Nusantara. Salafi and Wahhabi-influenced groups, strengthened by decades of translated literature and Gulf funding, charge it with syncretism and pre-Islamic Javanese residue. Muhammadiyah, the large modernist organisation founded in 1912, has historically been closer to the critics. This argument, between two of the largest religious organisations in the world, is the main internal dynamic of Indonesian Islam and almost never appears in Western accounts of the religion.