Question: few compositions for the organ were left by a composer of what nationality?

Context paragraphs:
Jonathan Rennert: Jonathan Rennert (17 March 1952) is an English organist, conductor and writer.  He gave his debut broadcast organ recital at the age of 19 in Westminster Cathedral, having become a Fellow of the Royal College of Organists at 18.  ('A force to be reckoned with', opined the reviewer in 'Music & Musicians'.)  He studied at the Royal College of Music under Richard Popplewell, John Barstow and William Lloyd Webber, and at Cambridge (where he was organ scholar of St John's College) under George Guest and Gillian Weir.  Awards included Cambridge University's John Stewart of Rannoch Scholarship in Sacred Music and 'Greater London Arts Association Young Musician 1975'.  Short periods based in London and Ottawa were followed by his appointment in 1979 as Director of Music of St Michael's Cornhill, the church which has been his base for 32 years.  Here he has given more than 400 of the weekly lunchtime organ recitals, and continued the musical traditions of such predecessors as William Boyce (the 18th-century composer) and Harold Darke.  He has tended to specialise in the music of J S Bach and romantic English composers, though he also gives first performances of new music.  He has given organ recitals in many countries, and in 'celebrity' series at the Royal Festival Hall, St Paul's Cathedral and Westminster Abbey, and was Musician-in-Residence at Grace Cathedral, San Francisco.  There are several CDs, including a choral disc of music by George Dyson in which Rennert conducted St Michael's Singers and the Royal Philharmonic Orchestra, and was commended by 'Gramophone' magazine: 'The performance is superb.  Rennert has the right sense of spaciousness and husbands his climaxes with measured artistry.'  Other choirs of which he has been chief conductor include the Elizabethan Singers and St Cecilia Chorus.  His writings include biographies of the infant prodigy and composer William Crotch, and of the organist George Thalben-Ball.  He has served as President of The Organ Club, Warden of the Incorporated Society of Musicians and Master of the Worshipful Company of Musicians.  He is a senior moderating examiner for the Associated Board of the Royal Schools of Music.

Frederik Magle: Frederik Reesen Magle (] ; born 17 April 1977) is a Danish composer, concert organist, and pianist.  He writes contemporary classical music as well as fusion of classical music and other genres.  His compositions include orchestral works, cantatas, chamber music, and solo works (mainly for organ), including several compositions commissioned by the Danish Royal Family.  Magle has gained a reputation as an organ virtuoso, and as a composer and performing artist who does not refrain from venturing into more experimental projects – often with improvisation – bordering jazz, electronica, and other non-classical genres.

Organ Sonatas (Bach): The organ sonatas, BWV 525–530 by Johann Sebastian Bach are a collection of six sonatas in trio sonata form.  Each of the sonatas has three movements, with three independent parts in the two manuals and obbligato pedal.  The collection was put together in Leipzig in the late 1720s and contained reworkings of prior compositions by Bach from earlier cantatas, organ works and chamber music as well as some newly composed movements.  The sixth sonata, BWV 530, is the only one for which all three movements were specially composed for the collection.  When played on an organ, the second manual part is often played an octave lower on the keyboard with appropriate registration.  Commentators have suggested that the collection might partly have been intended for private study to perfect organ technique, some pointing out that its compass allows it to be played on a pedal clavichord.  The collection of sonatas is generally regarded as one of Bach's masterpieces for organ.  The sonatas are also considered to be amongst his more difficult compositions for the instrument.

Jan z Lublina: Jan z Lublina, or Joannis de Lublin, was a Polish composer and organist who lived in the first half of the 16th century.  Not much is known about his life - he was a member of the Order of Canons Regular of the Lateran, circa 1540 he was possibly the organist at the convent in Kraśnik, near Lublin.  Perhaps he is identical to one of the two Jans, the first of which received his master's degree in artibus et philosophia in 1499, and the second his baccalariatus in artibus in 1508 in the Kazimierz Academy in Krakow.  From 1537 to 1548, he created the famous organ tablature, whose title is "Tabulatura Ioannis de Lyublyn Canonic[orum] Reg[u]lariu[m] de Crasnyk."  This is the largest organ tablature in the world (more than 350 compositions and a theoretical treatise) and one of the earliest.  It contains several compositions by Nicolaus Cracoviensis, as well as numerous intabulations of works written by Josquin, Heinrich Finck, Janequin, Ludwig Senfl, Claudin de Sermisy, Philippe Verdelot, Johann Walter, etc.

Sieben Stücke, Op. 145: Sieben Stücke für Orgel (Seven organ pieces), Op. 145, is a collection of seven compositions for organ by Max Reger.  He composed the work in three groups in 1915 and 1916.  The titles of seven individual character pieces reflect aspects of World War I and Christian feasts.  The compositions are based on traditional German hymns, sometimes combining several in one piece.  Reger's last work for organ, it was published, again in three installments, in 1915 and 1916.

Organ works (Bruckner): Although he was a proficient organist, Anton Bruckner left few compositions for the organ.

George Rosenkrans: George Rosenkrans (Jan 17, 1881-Aug.  18, 1955) was a noted American composer of concert band music.  He was born in Penfield, Pennsylvania on January 17, 1881.  His father was the music director of the local Methodist church, and George sang with the choir and learned to play the organ there.  His first compositions included organ music and hymns.  He also played the baritone horn in the town band, and eventually became the conductor.  He composed his first march at age 17, and was soon turning out as many as 8 new marches each year.  As interest in his music declined, he would sell new arrangements for as little as 50 cents, or give compositions away outright.  In later life, he composed many works for the Grampian Band in nearby Grampian, Pennsylvania, his favorite group, including the "Grampian March".  He missed a 1948 tribute by the Navy Band because he didn't believe he had any suitable clothes.  He died in poverty in Penfield on August 18, 1955.

Organ repertoire: The organ repertoire is among the largest for any solo musical instrument.  Because of the organ's (or pipe organ's) prominence in worship in Western Europe from the Middle Ages on, a significant portion of organ repertoire is sacred in nature.  The organ's suitability for improvisation by a single performer is well adapted to this liturgical role and has allowed many blind organists to achieve fame; it also accounts for the relatively late emergence of written compositions for the instrument in the Renaissance.  Although instruments are still disallowed in most Eastern churches, organs have found their way into a few synagogues as well as secular venues where organ recitals take place.

Anton Bruckner: Josef Anton Bruckner (] ; (1824--)04 1824 (1896--)11 1896 ) was an Austrian composer best known for his symphonies, masses, and motets.  The first are considered emblematic of the final stage of Austro-German Romanticism because of their rich harmonic language, strongly polyphonic character, and considerable length.  Bruckner's compositions helped to define contemporary musical radicalism, owing to their dissonances, unprepared modulations, and roving harmonies.

Clavier-Übung III: The Clavier-Übung III, sometimes referred to as the German Organ Mass, is a collection of compositions for organ by Johann Sebastian Bach, started in 1735–36 and published in 1739.  It is considered Bach's most significant and extensive work for organ, containing some of his musically most complex and technically most demanding compositions for that instrument.

Supporting paragraphs: Organ works (Bruckner) Anton Bruckner
Answer: Austrian