Actually,
The best horns were those built on the part of the Moon's cycle called the "New Moon," when the gravitational pull of the Moon has the least impact on things on the earth.
Even more specifically, the top players wanted a horn built during one of two times during that 24 hour day of the New Moon peak when the moon was least likely to be directly overhead or directly under foot for even less gravitational pull on the horn as it was being assembled!
All horns have to be totally stress free in order to ring and resonate to their peak efficiency . . . thus the great desire by those "in the know" to get a horn assembled during the peak day of the New Moon.
Of course, this is stunningly logical if you think about it . . . but I'm pulling your leg . . . I think!
Everyone have a great day!
Tom