The show's massive success in the mid-2000s and early 2010s spawned a number of imitating singing-competition shows, such as Rock Star, Nashville Star, The Voice, Rising Star, The Sing-Off, and The X Factor. Its format also served as a blueprint for non-singing TV shows such as Dancing with the Stars and So You Think You Can Dance, most of which contribute to the current highly competitive reality TV landscape on American television.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): What is another singing show similar to American Idol? 
The Voice