Buy a house with a very large carriage house with two levels, or very large barn with two levels, then convert the barn into four spaces (each with 12' or higher ceilings and dimensions that fall within the perfect acoustical room ratios found in AES research studies).
One space for a Home Theater and surround sound reproduction, optimized for surround sound music more so than actual movies - though definitely very comfortable and usable for a Home Theater.
One space for orchestra, or other large band music ensembles, where the speakers can be spaced very wide apart and reproduce the proper scale.
One space for rock music recording playback, with smaller scale.
One space as a recording studio, with space to store instruments and a drum kit, as well as filled with the proper speakers and amplifiers so people could just bring their instruments over and play without much hassle. Wtih another space for the actual recording equipment (recording booth, etc).
On top of all of that, I would have everything acoustically engineered from the very start, from the ground up before starting any construction. I would completely isolate every room and suspend them. I would not hold out on any measure to improve the rooms' sound. I would have it tested afterwards thoroughly with the speakers chosen to be in each room and make sure that the rooms were redesigned to fix any issues that weren't ironed out in the pre-design.
I guess in about 15 years my youngest kid will leave for college and I can start looking for the new house somewhere cheaper than Westchester County. Perhaps in Montana near Ted Turner's estates, with a large enough generator to power the house in case the power goes out for a month or longer (we have a great generator at our current house but it only powers everything in the house for about two weeks).