124. What is the best method of proceeding, if we wish to ensure the presence of a particular partial in the tone from a stretched string ?
125. Explain clearly how nodes are formed in a stretched string. Give an experiment in illustration.
126. What are the principal circumstances, which determine the presence and relative intensities of partials, in the tones of stringed instruments ?
127. Explain fully the effect of pressing down the loud pedal in pianoforte playing.
128. I press down the loud pedal of a pianoforte and strike Ejj in the Bass Clef sharply; name the strings that will be set in vibration.
129. How can a Tuning Fork be used, to produce vibrations in a stretched string ?
130. Explain how the material of the hammer and the kind of blow, affect the quality of tone in the pianoforte ?
131. Describe the phenomenon of the reflection of a sound wave at the end of an open pipe.
132. Describe the phenomenon of the reflection of sound at the end of a stopped pipe.
133. Define the terms node and ventral segment as applied to organ pipes.
134. Explain clearly how a node is formed in an open organ pipe.
135. Explain how nodes are formed in a stopped organ pipe.
136. Show by diagrams the positions that the nodes may take in an open organ pipe, and state the pitch of the tone produced in each case relatively to the fundamental tone of the pipe.
137. Do the same with regard to a stopped organ pipe,
138. Explain why only the odd series of partial tones occurs in the tones from stopped organ pipes, while open pipes give the complete series.
139. What is the difference between Harmonics on the one hand, and Overtones or Partials on the other?
140. Explain the principle of mixture stops on the organ—the " Sesquialtera " for example.
141. Describe an experimental method of proving the existence of nodes in an organ pipe.
142. I have two organ pipes each 4ft. 4in. long, one stopped and the other open. Calculate the approximate pitch of the fundamental tone in each.
143. What will be the pitch (approximate) of an open organ pipe 6ft. 6in. long? What would be the approximate pitch if it were stopped ?