The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
The formula that Burt Bacharach and Hal David used to achieve such remarkable success in the 1960s was the following.
These two creative artists dare to use different and unconventional forms. Their melodic leaps were wide, the chords they used were unusual. The progressions they used were unusual too and they played irregular rhythms.
Hal David was a great lyricist and Burt Bacharach was a phenomenal composer. They met each other in 1957 and started to work together. They already had a hit with the song "The Story of My Life," when they were hired to work with African American singer Dionne Warwick. They produced many hit songs such as "Wishing and Hoping," and "DO you Know the Way to San Jose."