One of the defining traits of language is its capacity to mediate between concepts in our mind, which encapsulate generalizations, and the things they refer to in a given communicative act, with all their idiosyncratic properties. This article examines precisely this interplay between conceptual and referential aspects of meaning, and proposes that concept composition (or concept combination, a term more commonly used in Psychology) exploits both: Conceptually afforded composition is at play when a modifier and its head fit as could be expected given the properties of the two concepts involved, whereas in referentially afforded composition the result of the composition depends on specific, independently available properties of the referent. For instance, red box tends to be applied to boxes whose surface is red, but, given the appropriate context, it can also be applied to e.g. a brown box that contains red objects. We support our proposal with data from nominal modification, and explore a way to formally distinguish the two kinds of composition and integrate them into a more general framework for semantic analysis. Along the way, we recover the classically Fregean notion of sense as including conceptual information, and show the potential of distributional semantics, a framework that has become very influential in Cognitive Science and Computational Linguistics, to address research questions from a theoretical linguistic perspective.