The paper introduces a novel approach for crowd curation of ambient music played in venues using physical Near Field Communication (NFC) enabled check-ins. The CheckinDJ jukebox system uses NFC enabled objects that are linked to individuals social network accounts. CheckinDJ can thus be regarded as a crowdsourced DJ that curates an evolving music playlist based on the musical preferences of those present at a location at any given time. In this paper we present the design and operation of the currently deployed system along with highlights of the promising potential of this novel concept.