Sphere Music Hall is a massive building. Upon its roof is a horizontally stretched sign bearing the words "Sphere Music Hall" in cursive writing. Directly inside the front entrance is a large reception hall with a stage. Hidden in the back are four doors, which have constellations on them. Each door leads to the same ring-shaped private room, where the Starlight Four would put on performances for those who attend the closed events. Said room contains an abundance of recliner chairs set in a circle facing a magic lantern. To the side of the room are double doors; through them is a check-patterned hallway.
Beyond the hallway is a door, through which is a facility where blood transfusion experiments are conducted; the facility contains a wide array of advanced equipment, tools, and beds, as well as numbered cabinets where bottles of blood, organized by names of stars (Polaris, Vega, Canopus, and Sirius; the amount of Sirius blood is the lowest compared to the other three), are stashed. Beyond said facility is a corridor from which doors lead to the rooms of "those with the names of stars."
Tradesmen enter and leave the music hall on a daily basis, transferring various items such as costumes designed by Hopkins' Tailor Shop. Nina Hopkins has been commissioned to create costumes for everyone, ranging from the Starlight Four to "those with the names of stars," at Sphere Music Hall. She also makes Grecian robes for the special event attendees. The robes, with their loose silhouette, have a unisex look that, according to Nina, can be worn by virtually anyone of any gender or age.
While the Starlight Four are highly regarded at the music hall, four individuals, who are sometimes called "those with names of stars," are superior to them. The four individuals are Lord Sirius, Lord Canopus, Lord Vega, and Lord Polaris. They are considered the embodiments of the four guardian stars.
The music hall receives financial support from people with vast wealth to cover the expenses for its gatherings, where entry, food, and drink are free; bracelets of pure silver; and facilities where blood transfusion experiments are carried out. Some of the patrons of the music hall are members of the military, the House of Lords, and Scotland Yard. The reason they fund the operations is that many of them suffer from renal failure. Thus, they pay for their thickened, toxic blood, which their failing kidneys are unable to filter out, to be replaced with fresh blood à la blood transfusions. The replacement process is carried out by certain machines stored in a half-built second music hall in Bath.
Sphere Music Hall allows every individual, regardless of their social class, to attend the parties organized there every Saturday night, as long as the person wishing to attend has a written invitation; the written invitation is a slip of paper, upon which reads: Sphere Music Hall on Saturdays at eight o'clock. We would like you to invite you to come and enjoy with us. Please feel free to invite your family and friends.
The parties the music hall throws are unprecedented, because class discrimination is discouraged there. The parties are supposedly so captivating to the masses that the road in front of the hall tends to teem with carriages on Saturday nights. Men and women of all ages, whether they are aristocrats or laborers, mingle together and appear to be infatuated with the multitude of festivities. The attendees, as observed by Sebastian Michaelis, are "fanatics" whose fervor would not be quelled, even if the music hall were to be destroyed.
The parties feature music, singing, dancing, free food provisions, which are especially sought after by poverty-stricken children, and Blavat Sky's fortune readings, which are renowned for their outstanding accuracy.
These parties customarily commence at eight o'clock, and would end at eleven o'clock, but before the assembly of people is dismissed, everyone would sing a song together, as a tradition—the practice is referred to as "carolling."
There are a couple of exceptions regarding the customs at Sphere Music Hall. Every fourth Saturday, for instance, a special performance by the Starlight Four would be arranged. Moreover, while the Saturday meetings are open to anyone, there are closed events that only those who have had their fortunes told can attend; they are permitted entrance into a certain room as long as they have the bracelets of pure silver Blavat gives out.
Blavat Sky, through his fortune readings offered at the music hall, determines which of the four stars (Sirius, Canopus, Vega, and Polaris; Sirius is the rarest, as it is a star of the first magnitude) the person is under the divine protection of, and every individual who has their fortune told receives a bracelet of pure silver. The design of the bracelet is based on whichever star the wearer is protected by.
For his divination, Blavat mainly uses a cup engraved with horoscope symbols; the cup would be filled with a special clear liquid. He carries a needle so that his customers can prick their fingers—since dropping blood into the cup is a required step for him to read his customers' fortunes—as well as some gauze to treat the bleeding fingers. He also has a bucket, where he would dispose of the blood-tainted liquid.
In reality, the divination is a ruse, and Blavat is actually blood-typing the music hall attendees. A chemical reaction activates when a person's blood comes into contact with the special clear liquid, and from that Blavat is able to classify the person's blood type.
The Starlight Four or "S4" are Sphere Music Hall's choir. They are mandated to perform every fourth Saturday to the general public at the music hall, and regularly at closed events. The S4 are composed of Herman Greenhill, Edgar Redmond, Lawrence Bluewer, and Gregory Violet. Blavat Sky produces their songs and clothing, and is always present at their fittings. He also supervises them during their rigorous dance lessons. Both the S4 and Blavat are considered "charismatic celebrities" to the populace of London.
During their fourth-Saturday performances, the Starlight Four would typically be accompanied by a supporting choir, who would sing the hymn with them. After the hymn is sung, the supporting choir would exit the stage. The Starlight Four would, then, remove their robes, and perform their own song.
Sphere Music Hall hosts closed events reserved for those in possession of the pure silver bracelets Blavat Sky distributes. These events are held on different days of the week: Polaris on Mondays and Wednesdays, Vega on Tuesdays, Canopus on Thursdays, and Sirius on Fridays. There is a large area in the back with four doors, where the bracelet owners would go. They would be made to change into a Grecian robe, and continue through one of the doors to a private room, where a meal and an exclusive performance by the Starlight Four would be provided. Those attending the closed events would typically be drugged to sleep by a "perfume," and their blood would be secretly drawn. When the attendees eventually wake up, they would be handed snacks and juice.
Sphere Music Hall covertly performs blood transfusions on their attendees during closed events and stores their blood at a facility in the back of the building. The quantities of the four different blood types are skewed disproportionately: Polaris makes up 44%, Vega 44%, Canopus 10%, and Sirius 2%.
The success rate for blood transfusions is extremely low, and, thus, the number of fatalities is quite substantial. The music hall buries their corpses in Epping Forest, East of London. According to Inspector Abberline, the corpses are "near pristine," for they do not bear any external wounds, and postmortem bruising is scarce. The classes and professions of the deceased greatly vary. Their deaths are the result of "multiple organ failure due to loss of blood."