In music, a note is a symbol denoting a musical sound. In English usage a note is the sound itself. Notes can represent the duration of a sound in musical notation. A note can represent a pitch class. Notes are the building blocks of much written music: discretizations of musical phenomena that facilitate performance and analysis; the term note can be used in both generic and specific senses: one might say either "the piece'Happy Birthday to You' begins with two notes having the same pitch", or "the piece begins with two repetitions of the same note". In the former case, one uses note to refer to a specific musical event. Two notes with fundamental frequencies in a ratio equal to any integer power of two are perceived as similar; because of that, all notes with these kinds of relations can be grouped under the same pitch class. In traditional music theory, most countries in the world use the solfège naming convention Do–Re–Mi–Fa–Sol–La–Si, including for instance Italy, Spain, Romania, most Latin American countries, Albania, Turkey and all the Arabic-speaking or Persian-speaking countries.

However, in English- and Dutch-speaking regions, pitch classes are represented by the first seven letters of the Latin alphabet. A few European countries, including Germany, adopt an identical notation, in which H substitutes for B. In Indian music the Sanskrit names Sa–Re–Ga–Ma–Pa–Dha–Ni are used, as in Telugu Sa–Ri–Ga–Ma–Pa–Da–Ni, in Tamil. Byzantium used the names Pa–Vu–Ga–Di–Ke–Zo–Ni; the eighth note, or octave, has double its frequency. The name octave is used to indicate the span between a note and another with double frequency. To differentiate two notes that have the same pitch class but fall into different octaves, the system of scientific pitch notation combines a letter name with an Arabic numeral designating a specific octave. For example, the now-standard tuning pitch for most Western music, 440 Hz, is named a′ or A4. There are two formal systems to define each note and octave, the Helmholtz pitch notation and the scientific pitch notation. Letter names are modified by the accidentals.

The sharp sign ♯ raises a note by a semitone or half-step, a flat ♭ lowers it by the same amount. In modern tuning a half step has a frequency ratio of 12√2 1.0595. The accidentals are written after the note name: so, for example, F♯ represents F-sharp, B♭ is B-flat, C♮ is C natural. Additional accidentals are the double-sharp, raising the frequency by two semitones, double-flat, lowering it by that amount. In musical notation, accidentals are placed before the note symbols. Systematic alterations to the seven lettered pitches in the scale can be indicated by placing the symbols in the key signature, which apply implicitly to all occurrences of corresponding notes. Explicitly noted. A special accidental, the natural symbol ♮, is used to indicate a pitch unmodified by the alterations in the key signature. Effects of key signature and local accidentals do not accumulate. If the key signature indicates G♯, a local flat before a G makes it G♭, though this type of rare accidental is expressed as a natural, followed by a flat to make this clear.

A double sharp sign on a key signature with a single sharp ♯ indicates only a double sharp, not a triple sharp. Assuming enharmonicity, many accidentals will create equivalences between pitches that are written differently. For instance, raising the note B to B♯ is equal to the note C. Assuming all such equivalences, the complete chromatic scale adds five additional pitch classes to the original seven lettered notes for a total of 12, each separated by a half-step. Notes that belong to the diatonic scale relevant in the context are sometimes called diatonic notes. Another style of notation used in English, uses the suffix "is" to indicate a sharp and "es" for a flat, e.g. Fis for F♯, Ges for G♭, Es for E♭; this system first arose in Germany and is used in all European countries whose main language is not English, Greek, or a Romance language In most countries using these suffixes, the letter H is used to represent what is B natural in English, the letter B is used instead of B♭, Heses is used instead of B.

Dutch-speakers in Belgium and the Netherlands use the same suffixes, but applied throughout to the notes A to G, so that B, B♭ and B have the same meaning as in English, although they are called B, Beses instead of B, B flat and B double flat. Denmark uses H, but uses Bes instead of Heses for B; the following chart lists the names used in different countries for the 12 notes of a chromatic scale built on C. The corresponding symbols are shown within parenthesis. Differences between German and English notation are highlighted in bold typeface. Although the English and Dutch names are different, the corresponding symbols are identical; the table below shows each octave and the frequencies for every note of pitch class A. The traditional system centers on the great small octave. Lower octaves are named "cont

Robert Bush Sebra, is an American former professional baseball pitcher, who played in Major League Baseball for the Texas Rangers, Montreal Expos, Philadelphia Phillies, Cincinnati Reds, Milwaukee Brewers, in all or part of the 1985 to 1990 seasons. He batted right-handed. Born in Ridgewood, New Jersey, Sebra played prep baseball at Gloucester Catholic High School. Sebra attended the University of Nebraska–Lincoln, in 1981 he played collegiate summer baseball with the Wareham Gatemen of the Cape Cod Baseball League, he was drafted by the Texas Rangers in the 5th round of the 1983 Major League Baseball draft. Over the course of his big league career, he pitched in 52 of them as a starting pitcher. Included among his Sebra’s MLB highlights are 2 shutouts, accomplished while with Montreal. Career statistics and player information from MLB, or ESPN, or Baseball-Reference, or Fangraphs, or Baseball-Reference, or Retrosheet

HMS Sandwich was a Bridgewater-class sloop built by Hawthorn Leslie, Newcastle. After a decade of peacetime service on the China Station, she escorted Atlantic convoys through World War II. HMS Sandwich was ordered from Hawthorn Leslie on 19 September 1927, one of two Bridgwater-class sloops ordered from Hawthorn Leslie that day; the Bridgewaters were intended as replacements for the Flower-class sloops, were to combine the role of peacetime patrol work at distant overseas stations with a wartime role as minesweepers. Sandwich was 266 feet 4 inches long overall and 250 feet between perpendiculars, with a beam of 34 feet and a draught of 11 feet 5 inches. Displacement was 1,600 long tons full load; the ship was powered by two Parsons geared steam turbines, each driving one propeller shaft, using steam provided by two Admiralty three-drum boiler. The turbines developed a total of 2,000 shaft horsepower and were designed to give a maximum speed of 16.5 knots. The main armament consisted of a pair of QF four-inch Mk V guns on the ship's centreline, one forward and one aft, with the forward gun on a high-angle mount, capable of anti-aircraft fire and the second gun on a low-angle mount, for anti-surface use only.

Two 3-pounder saluting guns were carried, while the anti-submarine armament consisted of four depth charges. The ship's crew consisted of ratings. Sandwich was laid down at Hawthorn Leslie's Tyneside shipyard on 9 February 1928 and was launched without ceremony on 29 September. Sandwich reached a speed of 17.27 knots during sea trials and was commissioned on 23 March 1929. In 1938, the aft four-inch gun was replaced by one on a high-angle mounting and the two saluting guns were exchanged for a pair of quadruple Vickers 0.5 in anti-aircraft machinegun mounts. By the outbreak of the Second World War, the ship had been fitted with ASDIC, the depth charge outfit was increased to 15 charges. While ordered for service in the Persian Gulf, both Sandwich and her sister ship Bridgewater were first deployed to the China Station, replacing the old sloops Foxglove and Bluebell, she was recommissioned with a new crew at Hong Kong in October 1931. Sandwich, along with the cruiser Cornwall was based at Shanghai during the Shanghai Incident in early 1932.

She again received a new crew at Hong Kong in April 1934. When the British owned steamer Tungchow went missing on 31 January 1935 on a voyage between Shanghai and Yantai, having been seized by pirates, Sandwich was one of several warships despatched to search for the missing ship; the pirates abandoned Tungchow when the ship was spotted by aircraft from the aircraft carrier Hermes. In January 1938, as the Second Sino-Japanese War continued, Sandwich landed men at Weihaiwei to protect British property against rioting as Japanese forces advanced towards the city; the ship was refitted at Hong Kong from April to October 1938, recommissioning with a fresh crew in March 1939. Sandwich was based at Hong Kong when war was declared, patrolled the Tsushima Strait for German merchant shipping before sailing east in November 1939 to return to the United Kingdom in December with convoy HG 11, she escorted convoys between Liverpool and Gibraltar until May 1940 and coastal and Western Approaches convoys rescuing survivors from the sunken freighters King Idwal and Anten of convoy OB 244 in November 1940.

Sandwich began refit at Tilbury in December and resumed convoy escort duties in April 1941 assigned to the 43rd Escort Group. Type 271 radar was installed during refit at Belfast from January through March 1942, the original.50 caliber anti-aircraft machine guns were replaced with Oerlikon 20 mm cannon during a shorter refit in October. Sandwich was credited with sinking U-213 while escorting convoy OS 35, escorted convoys in support of Operation Torch until refit on the River Tyne from February through July 1943. Upon completion of trials and workup, Sandwich escorted convoys between Liverpool and Sierra Leone as part of the 38th Escort Group from August 1943 until retirement in June 1944. Planned refit at Brindisi was not completed, the ship was towed to Bizerte in 1945, she was sold there in 1946 for possible mercantile service, but scrapped after conversion was abandoned. Brown, David K. Atlantic Escorts: Ships, Weapons & Tactics in World War II. Barnsley, UK: Seaforth Publishing. ISBN 978-1-84415-702-0.

Gardiner, Robert. Conway's All The World's Fighting Ships 1922–1946. London: Conway Maritime Press. ISBN 0-85177-146-7. Hague, Arnold; the Allied Convoy System 1939–1945. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-019-3. Hague, Arnold. Sloops: A History of the 71 Sloops Built in Britain and Australia for the British and Indian Navies 1926–1946. Kendal, England: World Ship Society. ISBN 0-905617-67-3. Lenton, H. T.. J.. British and Dominion Warships of World War II. Garden City, New York: Doubleday and Company. Parkes, Oscar, ed.. Jane's Fighting Ships 1931. Newton Abbot, UK: David & Charles. ISBN 0-7153-5849-9. Rohwer, Jürgen. Chronology of the War at Sea 1939–1945: The Naval History of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2