Johnny Hartman and John Coltrane did an album together , and that 's just amazingly beautiful . They just work so well together , have such amazing respect for each other in the way John Coltrane will sit back and let Johnny sing , then step up at just the right time . Their use of one another 's strengths is fantastic .

Based on the preceding passage, choose your answer for question What does the text suggest about the frequency with which Johnny Hartman and John Coltrane worked together to create music ?
Select from: 1). None of the above choices .; 2). It seems to give the impression that they were a long time duo; 3). The text suggests that they worked together randomly over a number of years .; 4). It hints that the album was the only time that they collaborated together musically .;
The answer is:
4).