And nothing could offer the romantic musicians a finer opportunity for all this than the timbres of the orchestra. The soft golden tone of the horn, the brilliant yellow of the trumpet, the luscious green of the oboe, the quiet silver white of the flute seemed to stand ready for the poets of the senses to use at their pleasure. In the vibrating tone of orchestral instruments, even more than in complicated harmonies and appealing melodies, lay their chance for titillating the nerves of a generation hungry for sensuous excitement. But we must remember that if these instruments have poetic and colorful associations to us it is in large measure because there were romantic composers to suggest them. The horn and flute and oboe had been at Haydn’s disposal, yet he was little interested in the sensuous characteristics of them which we feel so acutely. In great measure the poetic and sensuous tone qualities of the modern orchestra were brought out by the romantic composers. The classical orchestra, as we have seen in an earlier chapter, had originally been based on the ‘string quartet’--namely, the first violins, the second violins, the violas, and the ‘cellos, with the double basses reënforcing the 'cello part. The string section completely supported the musical structure. This was because the strings alone were capable of playing complete and smooth scales and executing all sorts of turns and trills with nearly equal facility. Wind instruments in the eighteenth century were in a very imperfect condition. Some of them, like the trumpets, were capable of no more than eight or ten notes. All suffered from serious and numerous restrictions. Hence they were originally used for giving occasional color or ornamentation to the music which was carried by the strings. About the middle of the century the famous orchestra of the court of Mannheim, under the leadership and stimulus of Cannabich and of the Stamitz family, reached something like a solid equilibrium in the matter of instrumentation, and from its disposition of the strings and wind all later orchestration took its rise. The Mannheim orchestra became renowned for its nuance of effect, and especially for its organized crescendos and diminuendos. The ideal orchestra thus passed on to Haydn and Mozart was a ‘string quartet’ with wood-wind instruments for the occasional doubling of the string parts, and the brass for filling in and emphasizing important chords. Gradually the wood-wind became a separate section of the orchestra, sometimes carrying a whole passage without the aid of strings, and sometimes combining with the string section on equal terms. With this stage modern instrumentation may be said to have begun. The brass had to wait; its individuality was not much developed until Beethoven’s time.