I was reading an article on what makes a progressive rock band and it’s not easy to define. For instance:
long tracks sometimes extending beyond 20 minutes
songs having multiple time signatures
Excellent musicianship
Usually keyboards and lots of them
classical influences and sometimes classically trained musicians
abstract lyrics often accused of being meaningless/flowery
Rush in my opinion fall in to a few of those although their lyrics (much like Marillions ) were excellent
Of course the above are largely prog cliches but it’s hard to come up with a definitive list
I was reading the thread and thinking what defines a prog rock band and you posted this, it's a good definition, and sort of depends on the era as well, there haven't been many new ones over recent years.
The one's still going have tended to grow out of prog usually down to changes in personel, Genesis did, it Collins took 4 or 5 albums before he started to have a greater influence being more commercial, Gabriel really left prog behind when he went solo, Marillion found a new identity when Fish left. Floyd grew out of prog when Waters left then they individually played the old stuff to millions for years.
Yes and a few other bands still do a great job of earning a living by recreating old stuff on tour and not bothering about new stuff.
As for Rush, being a massive fan since the late 70's, I think they cross over several rock genres like no other, the first album (without Peart) was really Led Zep influenced, but after Peart joined his influence and lyric writing took them through prog rock 75-79, rock 80-84, keyboard influenced rock 85-89, rock again 91-96, the five year break saw them return in 2002 with Vapor Trails as heavy rock (not a keyboard in sight), Snakes and Arrows in 2007 has a definite Blues-Rock influence, and the final studio album Clockwork Angels combines nearly all of it, a concept album with classical string parts (definitely prog influenced), heavy guitar parts, and keyboard lead sections.