There's one little problem...
Randy California never copyrighted the opening notes to "Taurus..."
2. You can't copy-write backgrounds, only the melody.
And therefore there is no basis for a case claiming infringement over a commonly used musical phrase.
That's like saying that everyone who ever played Johnny B. Goode now owes Chuck Berry $1,000,000.00 dollars, it's not going to happen.
Sonny Boy Williamson wrote "One Way Out," and the Allman Brothers stole the credit.
Are you going to fight that one out in court too?
You see where this is headed.