A Message of Peace (Urdu:Paigham-e-Sulh) is the last book written by Mirza Ghulam Ahmad, the founder of the Ahmadiyya movement in Islam. The book was completed on 25 May 1908, a day earlier before his demise. The book was originally written in the Urdu language and has been translated to English.

Mirza Ghulam Ahmad wrote this fifty page book in two days, finishing it a day before his demise of May 26, 1908. He had planned to read this piece of work on May 26, 1908 at Ahmadiyya Building in Lahore. However, he died after a very brief illness. It was, however, published in a booklet form.

The main focus relayed in this booklet by Mirza Ghulam Ahmad is the gap between the Hindus and Muslims of India due to the mutual hatred and differences in cultures. In this, he made a fervent urgent appeal and declared that the teaching of Islam inculcates respect and reverence for each other's religious values and sensibilities. Moreover, he states the spiritual statuses of Rama , Chanderji and Krishna, as divine saints and the Vedas as being one of many books of God.

In 1947, the United Nations General Assembly declared 24 October, the anniversary of the Charter of the United Nations, as which "shall be devoted to making known to the peoples of the world the aims and achievements of the United Nations and to gaining their support for" its work.

In 1971 the United Nations General Assembly adopted a further resolution (United Nations Resolution 2782) declaring that United Nations Day shall be an international holiday and recommended that it should be observed as a public holiday by all United Nations member states.

United Nations Day is devoted to making known to peoples of the world the aims and achievements of the United Nations Organization. United Nations Day is part of United Nations Week, which runs from 20 to 26 October.

United Nations Day has traditionally been marked throughout the world with meetings, discussions and exhibits about the achievements and goals of the organization. In 1971, the General Assembly recommended that member states observe it as a public holiday.

Concert pitch refers to the pitch reference to which a group of musical instruments are tuned for a performance. Concert pitch may vary from ensemble to ensemble, and has varied widely over musical history. This is also referred to as the reference frequency for "A" in an orchestra, the term "concert pitch" being used to indicate the difference between "written" and "sounding" notes in scores.

To avoid ambiguity when referring to pitches on transposing instruments, the term concert pitch is here used to refer to the pitch on a non-transposing instrument. In the literature this is also called international standard pitch. Music for transposing instruments is transposed into different keys from non-transposing instruments—for example, playing a written C on a B♭ clarinet or trumpet produces a non-transposing instrument's B♭. This pitch is referred to as "concert B♭".

The A above middle C is often set at 440 Hz although other frequencies are also used, such as 442 Hz and 443 Hz. Historically, this A has been tuned to a variety of higher and lower pitches.

Stevland Hardaway Morris (born May 13, 1950 as Stevland Hardaway Judkins), known by his stage name Stevie Wonder, is an American singer, songwriter, and multi-instrumentalist, a child prodigy who developed into one of the most creative musical figures of the late 20th century. Blind since shortly after birth, Wonder signed with Motown's Tamla label at the age of eleven, and continues to perform and record for Motown to this day.

Among Wonder's best known works are singles such as "Superstition", "Sir Duke", "I Wish" and "I Just Called to Say I Love You". Well known albums also include Talking Book, Innervisions and Songs in the Key of Life. He has recorded more than thirty U.S. top ten hits and received twenty-two Grammy Awards, the most ever awarded to a male solo artist. Wonder is also noted for his work as an activist for political causes, including his 1980 campaign to make Martin Luther King, Jr.'s birthday a holiday in the United States. In 2009, Wonder was named a United Nations Messenger of Peace. In 2008, Billboard magazine released a list of the Hot 100 All-Time Top Artists to celebrate the US singles chart's fiftieth anniversary, with Wonder at number five.