2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/229322To illustrate the campaign to extend our knowledge of the charmonium spectrum, I focus on a puzzling new state, $X(3872) \to π^+π^- J/ψ$. Studying the influence of open-charm channels on charmonium properties leads us to propose a new charmonium spectroscopy: additional discrete charmonium levels that can be discovered as narrow resonances of charmed and anticharmed mesons. I call attention to open issues for theory and experiment.11 pages, 11 figures, uses espcrc2.sty (included); presented at BEACH 2004, 28 June - 3 July, IIT/ChicagoHigh Energy Physics - Phenomenologytext