Domain-Specific Modelling Languages (DSLs) allow domain experts to create models using abstractions they are most familiar with. A DSL’s syntax is specified in two parts: the abstract syntax defines the language’s concepts and their allowed combinations, and the concrete syntax defines how those concepts are presented to the user (typically using a graphical or textual notation). However important concrete syntax is for the usability of the language, current modelling tools offer limited possibilities for defining the mapping between abstract and concrete syntax. Most often, the language designer is restricted to defining a single icon representation of each concept, which is then rendered to the user in a (fixed) graphical interface. This paper presents a framework that explicitly models the bi-directional mapping between the abstract and concrete syntax, thereby making these restrictions easy to overcome. It is more flexible and allows, amongst others, for a model to be represented in multiple front-ends, using multiple representation formats, and multiple mappings. Our approach is evaluated with an implementation in our prototype tool, the Modelverse, and by applying it on an example language.