arXiv:2610.33974v1 Announce Type: new Abstract: Sperm-whale codas are usually described by the number and timing of their clicks. Earlier acoustic studies showed that individual clicks and longer coda sequences contain additional organization. We ask how that organization compares with music, whose smaller sounds also form larger units and ordered sequences. We compare codas with performed violin music, drum grooves, and sung melodies. Their sequences resemble music in some measures of predictability, yet codas show a different relationship between the smaller sounds within a unit and the order of units across a sequence. This combination was not observed in the musical references tested. Coda timing also varies coherently and carries information about individual callers. The recordings show another striking property: broad, reproducible variation along acoustic dimensions associated with human ratings of emotion, with a range comparable to human audio in most eligible tests. These findings motivate an acoustic blueprint that describes natural codas beyond their click timing. Its importance is apparent in synthetic audio: WhAM produces recognizable coda-like recordings, yet the tested clips remain distinguishable from natural codas in five of six acoustic comparisons after strict matching. The blueprint provides a fuller way to study natural codas and to evaluate how faithfully synthetic recordings represent them.