1. 5. Acoustic Guitar
Usually one of the families: classical, flamenco, flattop (or folk), archtop
Guitar construction:
Six strings (of steel or gut)
Tuned to E2, A2, D3, G3, B3, E3 (82, 110,147,196, Hz)
What are intervals? (A fourth except for the major third between B and G)
A matched set of strings have carefully adjusted masses so that the strings are tuned to the correct intervals when the tensions are the same (to keep strings from putting any distorting torque on the instrument)
Top plate made of spruce or cedar (thickness about 2.5mm)
Brazilian rosewood is favored for making the backs and sides of a guitar because it is very hard and tends to contribute to a brighter sound (also mahogany, or maple)
A round hole 3 1/4" to 3 1/2" in diameter in the top plate creates a cavity resonance which strengthens the sound produced
Top and back are braced to strengthen plates and to transmit vibrations from the bridge
Bridge transfers vibrational energy of strings to the top plate
Frets (metal inserts) placed by fret rule: "one-eighteenth the remaining length of the string“

2. Fret Rule for Guitars
To provide for definite pitch relations between notes, metal inserts called frets are inset in a fretboard on the neck of guitars. The raised edges of the frets provide fixed lengths of string when the string is held down against them with a finger. The interval between successive frets is normally one equal tempered semitone.
Frets on guitars are placed by the fret rule "one-eighteenth the remaining length of the string". This makes them approximately a semitone apart. If the musical interval produced by this rule is expressed in cents, then a string of length 17/18 of its original length will be higher by an interval of 98.9 cents compared to a precise semitone of 100 cents. Since the just noticeable difference in pitch is about 5 cents, then the fret rule could be applied for one change of fret with no problems in intonation. One would have to be careful about cumulative errors if the rule were applied repeatedly, so it should be checked at intervals such as the musical fourth which should be precisely 3/4 of the length of the open string

3. History
The Spaniard Antonio de Torres Jurado is credited with considerable enhancements of the modern classical guitar in the mid nineteen hundreds. The body and the sound hole were enlarged and the fretboard widened. Perhaps his most important contribution was the development of "fan strutting", a series of struts which diverge from the sound hole on the top plate of the instrument. This design gave it a considerably stronger, more sustained tone.

4. 6a. There are several varieties of electric basses
6. Electric Guitar
Electric guitar construction:
Most often made with solid bodies since they depend upon several electromagnetic pickups and amplifiers to produce the sound and are not dependent upon the resonance of the hollow body like the acoustic guitar
Several pickups allow the player to adjust the quality of the sound by choosing the amounts of signal used from each pickup
There are volume controls for pickups
Position control switch allows a quick selection of pickup combinations. It is possible to choose front pickup only, front and middle, middle only, back and middle and back only
6a. There are several varieties of electric basses

5. Brass Instruments
When the brass instrument is played, the player’s lips act as a valve, introducing puffs of air at just the right time to maintain oscillations of the air column
Construction:
Mouthpiece
Mouthpipe
Cylindrical section (with valves)
Bell

6. 1. Oscillations in a pipe 2. Bernoulli effect Trumpet:
61, 184, 306, 429 Hz
2. Bernoulli effect