During the first half of the 19th century, there was a resurgence of interest in the guitar, and figures emerged with great ability as players, composers and teachers. Their music, together with the studies and methods they produced, help to modernize the instruments. London, Paris, and Vienna became major centers for the guitar, which once again became fashionable and popular. One of the key figures, Fernando Sor (1778-1839) was born in Barcelona and studied music in the monastery of Montserrat, where he was forbidden to use a guitar. After leaving the monastery, he was influenced by the work of Federico Moretti and left Spain in 1813, settling in Paris. An outstanding virtuoso, Sor built a tremendous reputation across Europe and his first book of studies (Op. 6) contains important material. Sor produced a large body of work, ranging melodies. Among his best-known works are the Variations on a theme from Mozart’s the Magic Flute (Op. 9), Based on the melody  "Das Klingelt So Herrlich," the due for two guitars, L'Encouragement (Op. 34) and his highly creative Fantasy (Op. 54). The sonata Grand Solo is an exceptional piece reflecting influence from the keyboard composer Domenico Scarlatti. Sor also wrote a Method of the Guitar.

 Another Spaniard, Dionisio Aguado (1784-1849), also wrote a Method for Guitar (1825), which contains complex studies to develop right-hand techniques, including harmonic controle and rhythmic independence between thumb and finger; he used right-hand nails in contrast to Farnendo Sor. After moving to Pairs in 1826, he became friends which Sor and wrote extensively for the guitar, producing works such as Variations on the Fandango (Op. 16).

Mauro giuliani

 The Italian virtuoso Mauro Giuliani (1781-1829) settled in Vienna in 1806, where he made a tremendous impact. Vienna was one of the great musical centers and his concerts were attended by Ludwig van Beethoven, who pronounced that "the guitar is an orchestra in itself." He played duos with the pianist Johann Nepomuk Hummel, and as a soloist toured throughout Europe to great acclaim. He used unusual techniques, such as using his thumb for bass notes. An important moment in the development of the guitar was his Concerto No. 1 in a major for guitar and orchestra, which he performed in 1808. This was the first modern concerto for the instrument. It has strong melodic themes that are developed in the first movement. The second movement is slower, with a siciliana rhythm, and the final movement is a lively polonaise. Themes and motifs are exchanged between the guitar and the orchestra. He also wrote two further concertos and fine sonatas, and 22 duos for guitar with flute or violin. His Duo Concertant (Op.25) for violin and guitar in E minor and Gran Duetto Concertante (Op.52) for flute and guitar in a major stand out. His six Rossinianae (Op. 119-124), written during the 1820s, are based on themes by Rossini, and have a sophistication that marks the growing development of guitar music. Guiliani also wrote quartets with a terz guitar, which is tuned a third higher.

 Great figures played the guitar, including the composer Schubert (1797-1828), who stated: "the guitar is a wonderful instrument understood by few," and wrote songs with guitar accompaniment, and the brilliant Italian violin virtuoso Nicolo Paganini (1782-1840), who played the guitar to a high standard and wrote solo and chamber works for it, including the Grand Sonata in A.

 After the age of Sor and Giuliani, a younger generation of guitarists emerged who developed current trends and composed for guitar. Napoleon Coste (1806—83) wrote Grand Duo for two guitars and La Source du Lyson, and made arrangements of J. S. Bach. His music has a pianistic style, as does the work of Johann Kaspar Mertz (1806—56) known as "the Liszt of the guitar" - whose Bardenklange pieces are dazzling and energetic.

 The distinguished Italian Giulio Regondi (1822—72) wrote Reverie, an early tremolo piece, and flamboyant works, including Introduction et Caprice (Op. 23), which has fast tempos, rapid scale passages, and ornamentation conveying passionate intensity.

Francisco tarrega

 The Spanish guitarist Francisco Tarrega (1852 1909) studied with Julian Areas (1832-82) and made his debut at the age of eleven. He practiced long hours, becoming a tremendous virtuoso, and he toured extensively, paving the way for the modern classical guitar by adopting the new instruments built by Antonio de Torres and others. As an arranger, Tarrega made an important step in the evolution of the guitar repertoire by transcribing and arranging works originally written for other instruments by major composers such as J. S. Bach. Previously, very little serious music had been transcribed for guitar, and the repertoire was limited to works specifically composed for the instrument and some arrangements of popular and rather lightweight pieces. Tarrega made transcriptions of piano works by Chopin and contemporary Spanish composers Isaac Albeniz and Enrique Granados.

 As a composer, Tarrega wrote Capricho arabe (1888), which has an atmospheric Moorish flavor and contrasting moods, ranging from dark colors using a sixth string dropped to D to brighter melodic sections. His well-known study Kecuerdos de la Alhambra features a continuous rippling melody line, with the notes played with rapid tremolo with three fingers, supported by attractive arpeggios that are played with the thumb. Tarrega was an extremely influential teacher and he built up a close circle of admirers and pupils.