Muqrin bin Abdulaziz Al Saud (Arabic: مقرن بن عبدالعزيز آل سعود‎ ‎ ; born 15 September 1945) is a member of House of Saud who served as Crown Prince of Saudi Arabia from January to April 2015.
 He was Director General of Al Mukhabarat Al A'amah (Saudi Intelligence Agency) from 2005 to 2012.
 In July 2012, Muqrin was appointed King Abdullah's Advisor and Special Envoy with the rank of minister.
 On 1 February 2013, King Abdullah named him as Second Deputy Prime Minister, being the fifth Saudi royal to hold this position.
 This post was previously held by King Fahd, King Abdullah, Crown Prince Sultan, and Crown Prince Nayef.
 On 27 March 2014, he was named Deputy Crown Prince making him second in the line of succession behind his brother Salman bin Abdulaziz Al Saud.
 On 23 January 2015, upon King Abdullah's death and the accession of King Salman, Muqrin became Crown Prince and First Deputy Prime Minister.
 On 29 April 2015, King Salman replaced Prince Muqrin with Prince Muhammad bin Nayef as Crown Prince.
Frederik, Crown Prince of Denmark, Count of Monpezat, {'1': ", '2': ", '3': 'RE, SKmd', '4': "} (Frederik André Henrik Christian; born 26 May 1968) is the heir apparent to the throne of Denmark.
 Frederik is the elder son of Queen Margrethe II and Henrik, the Prince Consort.
Li Zhong (李忠) (643 – January 6, 665), courtesy name Zhengben (正本), formally Prince of Yan (燕王), was a crown prince of the Chinese dynasty Tang Dynasty.
 He was the oldest son of Emperor Gaozong (Li Zhi) and was created crown prince in 652 even though he was not the son of his then-wife Empress Wang.
 After Empress Wang was displaced by Empress Wu (later known as Wu Zetian) in 655, however, Li Zhong was caught in Empress Wu's crosshairs and was forced to yield the crown prince position to his younger brother Li Hong, born of Empress Wu, in 656.
 He was later further reduced to commoner rank and put under house arrest, and when the chancellor Shangguan Yi failed in his attempt to persuade Emperor Gaozong to depose Empress Wu in 664 and was executed, Empress Wu took the opportunity to accuse Li Zhong of being complicit in Shangguan's plans.
 Around the new year 665, Emperor Gaozong ordered Li Zhong to commit suicide.
 He was posthumously honored an imperial prince, but not a crown prince, during the second reign of his brother Emperor Zhongzong.
Emperor Jianwen of Liang (梁簡文帝) (2 December 503 – 551), personal name Xiao Gang (蕭綱), courtesy name Shizuan (世纘), nickname Liutong (六通), was an emperor of the Chinese Liang Dynasty.
 He was initially not the crown prince of his father Emperor Wu, the founder of the dynasty, but became the crown prince in 531 after his older brother Xiao Tong died.
 In 549, the rebellious general Hou Jing captured the capital Jiankang, and Hou subsequently held both Emperor Wu and Crown Prince Gang under his power, having Crown Prince Gang take the throne (as Emperor Jianwen) after Emperor Wu's death later that year.
 During Emperor Jianwen's reign, he was almost completely under Hou's control, and in 551, Hou, planning to take the throne himself, first forced Emperor Jianwen to yield the throne to his grandnephew Xiao Dong the Prince of Yuzhang, and then sent messengers to suffocate the former emperor.
Xiao Zhangmao (蕭長懋) (458–493), courtesy name Yunqiao (雲喬), nickname Baize (白澤), formally Crown Prince Wenhui (文惠太子, literally "the civil and benevolent crown prince"), later further posthumously honored as Emperor Wen (文皇帝) with the temple name of Shizong (世宗), was a crown prince of the Chinese dynasty Southern Qi.
 He was Emperor Wu (Xiao Ze)'s oldest son, but predeceased his father.
 After his death, his son Xiao Zhaoye became crown prince and eventually succeeded Emperor Wu, but was soon thereafter overthrown by Emperor Wu's cousin Xiao Luan, who took over the throne.
 By 498, all of Xiao Zhangmao's descendants had been exterminated.
Wilhelm, German Crown Prince (German: "Kronprinz Wilhelm von Preußen" ; 6 May 1882 – 20 July 1951) , full name Friedrich Wilhelm Victor August Ernst, was the eldest child of the future German Emperor Wilhelm II and his wife Empress Augusta Victoria, and the last Crown Prince of the German Empire and the Kingdom of Prussia.
 After the death of his grandfather Emperor Frederick III, Wilhelm became crown prince at the age of six, retaining that title for more than 30 years until the fall of the empire on 5 November 1918.
 During World War I, he commanded the 5th Army from 1914 to 1916 and was commander of Army Group German Crown Prince for the remainder of the war.
 Crown Prince Wilhelm became Head of the House of Hohenzollern on 4 June 1941 following the death of his father and held the position until his own death on 20 July 1951.
The Royal Academy of Music (Danish: "Det Jyske Musikkonservatorium") in Aarhus and Aalborg, Denmark, is a conservatoire and state institution under the auspices of the Danish Ministry of Culture, charged with responsibility for the further education courses in music, and for otherwise contributing to the promotion of musical culture in Denmark.
 The school is under the patronage of His Royal Highness Crown Prince Frederik.
Li Jiancheng (; 589 – July 2, 626), formally Crown Prince Yin (, literally, "the hidden crown prince"), nickname Pishamen (), was a crown prince of the Chinese dynasty Tang Dynasty.
 He was the oldest son of the founding emperor Emperor Gaozu (Li Yuan) and therefore was designated crown prince after the founding of the dynasty in 618.
 However, although he himself was fairly capable as a general, he was overshadowed by the contributions of his younger brother Li Shimin the Prince of Qin, and the brothers contended for power for years, with Li Jiancheng aided by another younger brother, Li Yuanji the Prince of Qi.
 In 626, Li Shimin, fearing that Li Jiancheng and Li Yuanji were about to kill him, laid an ambush for them at Xuanwu Gate outside the palace and killed them.
 Li Shimin then effectively forced Emperor Gaozu to yield the throne to him (as Emperor Taizong).
Deputy crown prince is a royal political position, being the third man in the kingdom.
 The holder of the position becomes crown prince in the event of the absence of the crown prince, and the king of the country in the event of vacant posts of the King and the Crown Prince at the same time.
 The position is known in Saudi Arabia, as a key position.
 There are also other designations, such as the Second Deputy Premier, Second Deputy Prime Minister and Mandate of the mandate of the Covenant.
Tuoba Huang (拓拔晃) (428 – July 29, 451), formally Crown Prince Jingmu (景穆太子) (literally "the decisive and solemn crown prince"), later further formally honored as Emperor Jingmu (景穆皇帝) with the temple name Gongzong (恭宗) by his son Emperor Wencheng, was a crown prince of the Chinese/Xianbei dynasty Northern Wei.
 He was the oldest son of Emperor Taiwu, and was created crown prince in 432 at the age of four, and as he grew older, Emperor Taiwu transferred more and more authority to him.
 However, in 451, he incurred the wrath of his father due to false accusations of the eunuch Zong Ai, and many of his associates were put to death.
 He himself grew ill in fear, and died that year.

Question: What is the name of the mother of the Crown Prince who is the patron of the Royal Academy of Music in Denmark?
Answer: Queen Margrethe II