In this modern era there are many things that we don't find historic, but just trends. However, there are exceptions like Donald Trump, the first person with no political experience at all to become president. But I am talking about people, songs, etc.
Such as Elvis, he was a historic singer! King of Rock. What would, today, this generation, be considered historic? Twenty One Pilots? Chainsmokers? They both have gained immense popularity over the last year. What about all of YouTube, possibly the most recognizable site ever. With the thousands of people making money off of filming their life or filming them playing video games. Could that be considered historic?
In the field of historic preservation, as codified by the program established by the US National Historic Preservation Act of 1966, as amended (and implemented by the National Park System and the various state historic preservation offices), there is a distinction made between "historical" and "historic." The distinction that separates these terms may be of use:
All things of the past are historical, that is they belong to a period of that past that is history and is the domain of the discipline of history.
Significant things are "historic." For example, a historical marker (that is a thing that describes a thing about the past, but which does not have significance in itself), identifies something historic about that location.
In this way, defining what is historical is easy - all things of the past, objectively belong in this realm. We would like to think that defining what is historic - that is, what is significant and important about the past including events and people - is something of an objective process. But it really isn't. Much of what defines what is historic - i.e. important - is in the argument made by someone who puts it forward, so your examples of various musical groups are simply awaiting the case to be made effectively in such a way that the larger community of historians (or even the public at large) acknowledges that these are historic, pivotal, significant, or in some ways important expressions of humanity from the past.
In addition, some of what makes something historic is a matter of survival. A humble shack is hardly historic until it is the last survivor of American architecture from the seventeenth century. We had an example of a humble house in the Virginia City Landmark Historic District in Nevada. It stood across the street from the courthouse, which with its grand architecture and as the center of local government was clearly "historic." The house was poorly cared for and of no obvious distinction. Until we found that it was one of two surviving Chinese laundries in the community. Suddenly its stock went up, and it became "historic" in its own right. Rare survivor and revealed, interesting story to tell, redefined the ordinary and made it historic.
Not everyone makes this distinction between these two terms, but I find it useful, and it is essential in evaluating material remains from the past. I believe it is useful in understanding other expression of the past as well - that is, when dealing with people and events without material remains.