The use of the word Lied in German-speaking countries covers a broad repertoire which is not limited to the romantic art song. Though the notion is apparently less discussed by theorists and musicians at the end of the 19th century than it was a hundred years before, its occurrences in German writings on music between 1875 and 1914 show that its definition remains variable. Not only the stylistic trends of this period, but also the rise of public concerts devoted to the genre, together with the massive publishing of songs question the identity of the Lied. The ‘simplicity’ (Einfachheit) and the ‘interiority’ (Innigkeit) recommended by critics reveal a tension between two excesses — virtuosity and complexity on the one side, triviality and ordinariness on the other side — that are associated with peripheric genres such as the opera, the cantata or even the etude. Furthermore, the naming of model composers (notably Schubert, Schumann or Franz) emphasizes the construction of a repertoire and provides norms for the composition of songs. Through the study of concert and score reviews published in periodicals between 1875 and 1914, the aim of this paper is to highlight the problems raised by the delimitation and the historiography of the song- genre in German-speaking areas at the end of the 19th century.