Oracle unpivot of table data Given the table PerformerTours with the columns:
FirstName, LastName, Date_1, City_1, State_1, Date_2, City_2, State_2, Date_3, City_3, State_3, Date_4, City_4, State_4

and the data
Donna, Summers, 01/01/20, Atlanta, Georgia
James, Taylor, 02/04/20, Miami, Florida, 04/11/20, Seattle, Washington
Bob, Dylan, 01/11/20, Buffalo, New York, 09/24/20, Nashville, Tennessee, 10/22/20, Chicago, Illinois, 12/12/20, Denver, Colorado
Kenny, Rankin, 06/30/20, Las Vegas, Nevada, 07/04/20, Boston, Massachusetts, 08/18/20, Cincinnati, Ohio

how can I unpivot the data to be as defined below using just Oracle SQL:
Donna, Summers, 01/01/20, Atlanta, Georgia
James, Taylor, 02/04/20, Miami, Florida
James, Taylor, 04/11/20, Seattle, Washington
Bob, Dylan, 01/11/20, Buffalo, New York 
Bob, Dylan, 09/24/20, Nashville, Tennessee
Bob, Dylan, 10/22/20, Chicago, Illinois
Bob, Dylan, 12/12/20, Denver, Colorado
Kenny, Rankin, 06/30/20, Las Vegas, Nevada
Kenny, Rankin, 07/04/20, Boston, Massachusetts
Kenny, Rankin, 08/18/20, Cincinnati, Ohio
Select FirstName, LastName, Date_1 as date, City_1 as city, State_1 as state
  From performertours
Union all
Select FirstName, LastName, Date_2, City_2, State_2
  From performertours where date_2 is not null
Union all
Select FirstName, LastName, Date_3, City_3, State_3
  From performertours where date_3 is not null
Union all
Select FirstName, LastName, Date_4, City_4, State_4
  From performertours where date_4 is not null