movements were in that form, then later last movements as well (for example Mozart's Prague Symphony), and eventually the "sonata principle" came to extend through an entire work. For example, Beethoven's String Quartet Op. 59 No. 2 was said to have all four movements in sonata form. By this, theorists such as Donald Tovey meant the academically laid-out sonata form. Charles Rosen has argued that, properly understood, this was always the case: that real sonata forms (plural) were always present, though this is not universally agreed on. As the 19th century progressed, the complexity of sonata form grew, as new ways of moving through the harmony of a work were introduced by Johannes Brahms and Franz Liszt. Instead of focusing exclusively on keys closely related in the circle of fifths, they used movement along circles based on minor or major triads. Following the trend established by Beethoven, the focus moved more and more to the development section. This was in line with the Romantic comparison of music to poetry. Poetic terms, such as "rhapsody" and "tone poem", entered music, and increasingly musicians felt that they should not take the repeats in symphonies because there was no dramatic or lyrical point to doing so. This changed their interpretation of previous sonata forms. The Romantic sonata form was an especially congenial mold for Brahms, who felt a strong affinity with the composers of the Classical era. Brahms adopted and extended Beethoven's practice of modulating to more remote keys in the exposition, combining this with the use of counterpoint in the inner voices. For example, his piano quintet has the first subject in F minor, but the second subject is in C sharp minor, an augmented fifth higher. In the same work, the key scheme of the recapitulation is also altered – the second subject in the recapitulation is in F sharp minor, rather than the F minor of the first subject. Another force acting on sonata form was the school of composers centering on Franz Liszt and Richard Wagner. They sought to integrate more roving harmonies and unprepared chords into the musical structure in order to attain both formal coherence and a full, expressive range of keys. Increasingly, themes began to have notes which were far from the original key, a procedure later labeled "extended tonality". This trend strongly influenced the next generation of composers, for instance Gustav Mahler. The first movements