first writer who extended the theory of "agogics" was Hugo Riemann in his book Musikalische Dynamik und Agogik (1884). The theory was based on the idea of using small changes of rhythm and tempo for expression. Riemann used the term "agogic accent", by which he meant accentuation achieved by lengthening of a note. The theory found many supporters. J. Alfred Johnstone called the idea of agogic accents "quasi tempo rubato." He also expressed his appreciation for this theory, saying that "modern editors are coming to recognize it as one of the important principles of expressive interpretation." In his illustration of agogic accents in the Mendelssohn's Andante and Rondo Capriccioso op. 14, Johnstone explains, that even though the rhythm consists of equal quarter notes, they should not be played the same length; the highest note of the phrase ought to be the longest while other notes shortened proportionally. One of the musicians known for using agogic accents in their playing was the violinist Joseph Joachim. Some writers compared this type of rubato to declamation in speech. This idea was widely developed by singers. According to Gordon Heller: "If groups of notes happen to occur, which have to be sung to one word, the student must be careful to make the first note very slightly longer – though only very slightly – than the rest of the group. Should a triplet be written by the composer, care must be taken here to make the first note of the three a trifle longer than the rest, and thus give a musicianly rendering of it. To hurry the time in such a pace would spoil the rhythm..." Melodic rubato Both of the theories described above had their opponents and supporters. There was one question, though, that emerged in reference to both. Regardless if a melody is released from strict note values by accelerando and ritardando or agogic accents, should the accompaniment follow the melody or remain strict in time? The latter means that the melody would be either behind or ahead of the accompaniment for a moment. Eventually, in spite of doubts of some, it has become a tradition that the accompaniment did not follow the flexibility of the melody. As Franklin Taylor writes: "It should be observed that any independent accompaniment to a rubato phrase must always keep strict time, and it is, therefore, quite possible that no note of a rubato melody