linguistic:paraphrasing, stylistic:tone, quality:corruption, quality:correction
Artistry

While Sinatra never learned how to read music well, he had a natural understanding of it, and he worked very hard from a young age to improve his abilities in all aspects of music. He could follow a lead sheet (simplified sheet music showing a song's basic structure) during a performance by "carefully following the patterns and groupings of notes arranged on the page" and made his own notations to the music, using his ear to detect semitonal differences.

Granata states that some of the most accomplished classically trained musicians soon noticed his musical understanding and remarked that Sinatra had a "sixth sense," which "demonstrated unusual proficiency when it came to detecting incorrect notes and sounds within the orchestra."

Sinatra was an aficionado of classical music, and would often request classical strains in his music, inspired by composers such as Puccini and Impressionist masters. His personal favorite was Ralph Vaughan Williams. He would insist on always recording live with the band because it gave him a "certain feeling" to perform live surrounded by musicians. By the mid-1940s, such was his understanding of music that after hearing an air check of some compositions by Alec Wilder, which were for strings and woodwinds, he became the conductor at Columbia Records for six of Wilder's compositions. The works were considered by Wilder to have been among the finest renditions and recordings of his compositions, past or present. Critic Gene Lees, a lyricist and the author of the words to the Jobim melody "This Happy Madness," expressed amazement when he heard Sinatra's recording of it on Sinatra & Company (1971), considering him to have delivered the lyrics to perfection.

Voice coach John Quinlan was impressed by Sinatra's vocal range, remarking, "He has far more voice than people think he has. He can vocalize to a B-flat on top in full voice, and he doesn't need a mic either". As a singer, early on, he was primarily influenced by Bing Crosby, but later believed that Tony Bennett was "the best singer in the business." Bennett himself claimed that as a performer, Sinatra had "perfected the art of intimacy." According to Nelson Riddle, Sinatra had a "fairly rangy voice," remarking that "His voice has a very strident, insistent sound in the top register, a smooth lyrical sound in the middle register, and a very tender sound in the low. His voice is built on infinite taste, with an overall inflection of sex. He points everything he does from a sexual standpoint".

Despite his heavy New Jersey accent, when Sinatra sang, his accent was barely detectable; according to Richard Schuller, his diction became "precise" while singing, and his articulation "meticulous." His timing was impeccable, allowing him, according to Charles L. Granata, to "toy with the rhythm of a melody, bringing tremendous excitement to his reading of a lyric." Tommy Dorsey observed that Sinatra would "take a musical phrase and play it all the way through seemingly without breathing for eight, ten, maybe sixteen bars." Dorsey was a considerable influence on Sinatra's techniques for his vocal phrasing with his own exceptional breath control on the trombone, and Sinatra regularly swam and held his breath underwater, thinking of song lyrics to increase his breathing power.

"He'd always been critical of his voice, and that only intensified as he got older. He never liked to discuss a performance afterward because he knew his voice wasn't as good as it used to be. If someone told him he'd been great, he'd reply, 'It was a nice crowd, but my reed was off' or 'I wasn't so good on the third number.' Strangely, in spite of his hearing problems, he had the most incredible ear, which often drove those he worked with nuts. There could be an orchestra of a hundred musicians, and if one played a bum note, he'd know exactly who was responsible."

—Barbara Sinatra on Sinatra's voice and musical understanding.

Arrangers such as Nelson Riddle and Anthony Fanzo found Sinatra to be a perfectionist who constantly drove himself and others around him, stating that his collaborators approached him with a sense of uneasiness because of his unpredictable and often volatile temperament.

Granata comments that Sinatra was almost fanatically obsessed with perfection to the point that people began wondering if he was genuinely concerned about the music or showing off his power over others. On days when he felt that his voice was not right, he would know after only a few notes and would postpone the recording session until the following day, yet still pay his musicians.

After a period of performing, Sinatra tired of singing a certain set of songs and was always looking for talented new songwriters and composers to work with. Once he found ones that he liked, he actively sought to work with them as often as he could and made friends with many of them. Over the years, he recorded 87 of Sammy Cahn 's songs, of which 24 were composed by Jule Styne and 43 by Jimmy Van Heusen. The Cahn-Styne partnership lasted from 1942 until 1954, when Van Heusen succeeded him as Sinatra's main composer.

Unlike many of his contemporaries, Sinatra insisted upon direct input regarding arrangements and tempos for his recordings. He would spend weeks thinking about the songs he wanted to record and would keep an arranger in mind for each song. Barbara Sinatra notes that Sinatra would almost always credit the songwriter at the end of each number and would often make comments to the audience, such as "Isn't that a pretty ballad" or "Don't you think that's the most marvelous love song," delivered with "childlike delight." She states that after each show, Sinatra would be "in a buoyant, electrically charged mood, a post-show high that would take him hours to come down from as he quietly relived every note of the performance he'd just given."

"His voice is more interesting now: he has separated his voice into different colors, in different registers. Years ago, his voice was more even, and now it is divided into at least three interesting ranges: low, middle, and high. probing more deeply into his songs than he used to. That may be due to the ten years he's put on and the things he's been through."

—Nelson Riddle noting the development of Sinatra's voice in 1955.

Sinatra's split with Gardner in the fall of 1953 had a profound impact on the types of songs he sang and on his voice. He began to console himself in songs with a "brooding melancholy," such as " I'm a Fool to Want You," " Don't Worry 'Bout Me," " My One and Only Love " and " There Will Never Be Another You," which Riddle believed was the direct influence of Ava Gardner.

Lahr comments that the new Sinatra was "not the gentle boy balladeer of the forties. Fragility had gone from his voice, to be replaced by a virile adult's sense of happiness and hurt". Author Granata considered Sinatra a "master of the art of recording," noting that his work in the studio "set him apart from other gifted vocalists." During his career, he made over 1000 recordings. Recording sessions would typically last three hours. However, Sinatra would always prepare for them by spending at least an hour by the piano beforehand to vocalize, followed by a short rehearsal with the orchestra to ensure the balance of sound.

During his Columbia years, Sinatra used an RCA Type 44 microphone, which Granata describes as "the 'old-fashioned' microphone which is closely associated with Sinatra's crooner image of the 1940s". At Capitol, he used a Neumann U 47, an "ultra-sensitive" microphone that better captured the timbre and tone of his voice.

In the 1950s, Sinatra's career was facilitated by developments in technology. Up to sixteen songs could now be held by the twelve-inch L.P., and this allowed Sinatra to use song in a novelistic way, turning each track into a kind of chapter, which built and counterpointed moods to illuminate a larger theme". Santopietro writes that through the 1950s and well into the 1960s, "Every Sinatra LP was a masterpiece of one sort of another, whether uptempo, torch song, or swingin' affairs. Track after track, the brilliant concept albums redefined the nature of pop vocal art".