Here is a question about this article: Burgh (2006), suggests that the roots of Western classical music ultimately lie in ancient Egyptian art music via cheironomy and the ancient Egyptian orchestra, which dates to 2695 BC. This was followed by early Christian liturgical music, which itself dates back to the Ancient Greeks[citation needed]. The development of individual tones and scales was made by ancient Greeks such as Aristoxenus and Pythagoras. Pythagoras created a tuning system and helped to codify musical notation. Ancient Greek instruments such as the aulos (a reed instrument) and the lyre (a stringed instrument similar to a small harp) eventually led to the modern-day instruments of a classical orchestra. The antecedent to the early period was the era of ancient music before the fall of the Roman Empire (476 AD). Very little music survives from this time, most of it from ancient Greece.
What is the answer to this question: Which ancient society developed individual tones and scales?
****
So... ancient Greeks

Here is a question about this article: The Lord Mayor's official residence is 3 Elliot Terrace, located on the Hoe. Once a home of Waldorf and Nancy Astor, it was given by Lady Astor to the City of Plymouth as an official residence for future Lord Mayors and is also used today for civic hospitality, as lodgings for visiting dignitaries and High Court judges and it is also available to hire for private events. The Civic Centre municipal office building in Armada Way became a listed building in June 2007 because of its quality and period features, but has become the centre of a controversy as the council planned for its demolition estimating that it could cost 40m to refurbish it, resulting in possible job losses.
What is the answer to this question: What did Plymouth council estimate the cost to refurbish the Civic Centre municipal office building to be?
****
So... 40m

Here is a question about this article: LEDs have been developed by Seoul Semiconductor that can operate on AC power without the need for a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficacy of this type of HP-LED is typically 40 lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named as 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design.
What is the answer to this question: What company has developed LEDs that can operate on AC power?
****
So...
Seoul Semiconductor