The first iterations only had four strings, but over time they added more and more until they ended up with eleven – sometimes thirteen. The strings make up 5 courses doubled and 1 single course, tuned to C-F-A-D-G-C. The absence of frets allowed for the exploration of unique scales and melodic nuances found in Arabic music.

The instrument is considered an ancient ancestor of the guitar, even being played with a plectrum resembling a larger version of a modern guitar pick. It is still really popular today, especially in places like Turkey, the Middle East, and North Africa.

At a certain point, Lute players favored fingerpicking which allowed them to play several different voices at the same time. Later versions added even more courses as over time more and more bass courses were added. The Lute featured gut strings and a fretboard, which enabled fixed pitches and faster playing. It also featured a bowl back, similar to the oud, and a bent-back peg box with friction-peg tuners.

Lute players used a combination of picks and fingers to play multiple voices simultaneously, creating intricate harmonies. The Lute was often used as an accompaniment instrument as its volume does not overpower the singing voice.

This guitar uses 7 strings with 4 courses – 3 doubled courses and 1 single course – tuned to G-C-E-A. When the Portuguese later brought this instrument to Hawaii, it became an inspiration for the ukulele. It featured gut strings wrapped around a fretboard, allowing for precise pitch control.

The instrument had a smaller size and fewer frets compared to the modern guitar but still offered the ability to play melodies and especially chords, which was easier due to the fewer number of strings.

This guitar’s 5 courses could all be doubled, but was generally played without the E being doubled. This instrument still featured a flat back, gut frets, and friction pegs. Baroque guitarists utilized techniques such as tremolo and played compositions that showcased the instrument's capabilities, often imitating operatic styles.

Towards the end of the 18th century, with the popularity of Gallant style music and a return to simpler melodies with accompaniment, more bass range was required and some Baroque guitars started to add the 6th, or low E, course.

The addition of metal strings in this period also required the gut frets to be replaced with metal, leading to the decision to use equal temperament as the frets could no longer be moved freely. Additionally, the extra tension from the metal strings led to the introduction of the pin bridge, exactly like our modern acoustic guitar.

It had a larger body, extended floating fretboard, and 22 frets, making it a more versatile instrument. Some also featured an early pre-truss rod mechanism that uses a clock key to change the angle of the neck.

The 19th-century guitar closely resembled the modern guitar in terms of size and tuning and featured advancements in construction techniques. This era of the guitar led to an explosion in its popularity with more people learning and playing their favorite operatic pieces of the time at home.

The dimensions of the guitar that Torres came up with is still used today in our modern classical guitar. This guitar also used metal gears for fine tuning and kept the metal frets of the 19th century guitar, though the strings were generally gut or nylon.

By around 1920, steel-string acoustic guitars became the predominant guitar and he had started one of the biggest guitar industries America has ever seen. Modern acoustic guitars are versatile instruments used in a wide range of musical genres and are characterized by their standardized shape, size, and tuning.