Arriaga's music is "elegant, accomplished and notable for its harmonic warmth" ("New Grove Concise Dictionary of Music"). His greatest works are undoubtedly the three string quartets, which (like his predecessors', D. Scarlatti, Soler and Boccherini) contain notably Spanish ethnic rhythmic and melodic elements, especially in the galloping 6/8 finale of No. 1 in D minor and the meditative second (slow) movements of No. 2 in A major (an impressive set of variations in D major taking off from the slow D major variation movements in Mozart's K. 464 and Beethoven's Op. 18 No. 5 (both also in A major as a whole), which climaxes in a D minor variation even more passionate than Mozart's D minor variation in K. 464, in the form of an impassioned, plangent lament on the top two strings of the viola going up to the second A above middle C) and No. 3 in E-flat major (a tender G major lullaby for the newborn Christ child). Periodwise, his style is on the borderline between late Classicism and early Romanticism, ranging from the late Classical idiom of Mozart to the proto-Romanticism of early Beethoven.