Either abc2midi or abc2xml complains if N: or Z: is the last header.

Session/MichaelTurnersWaltz.abc

@@ -1,11 +1,11 @@
 X: 1
 T: Michael Turner's Waltz
+Z: Cry Havoc Booke of Dottes. Creative Commons by-nc-sa 2.0 UK licenced.
 M: 3/4
 L: 1/8
 R: waltz
 Q: 140
 K: Gmaj
-Z: Cry Havoc Booke of Dottes. Creative Commons by-nc-sa 2.0 UK licenced.
 DGA | "G" B2 B2 "D" c2 | "G" d4 gf | "C" e2>f2 ge | "G" d2>"D" D2 GA |
         "G" B2 B2 "D" c2 | "G" d2>e2 cA | "G" G3 B "D" AF | "G" G3 :|
 AB | "D" c2>d2 cB | "D" A4 Bc | "G" d2>e2 dc | "Em" B4 gf |

Session/Railway.abc

@@ -1,10 +1,10 @@
 X: 1
 T: Railway, The
+N: Change: FieryClockFace.abc
 M: 6/8
 L: 1/8
 Q: 160
 K: Gmaj
-N: Change: FieryClockFace.abc
 D | "G" G2 G GBd | g2 d d2 d | "Am" e2 d c2 B | "D7" ABA FED |
     "G" G2 G GBd | g2 d d2 d | "C" edc "G" BAG | "D7" A3 "G" G2 :|
 d | "G" b2 b b2 a | g2 g g2 d | "C" e2 d efg | "D" a2 g fed |

Session/RoguesMarch.abc

@@ -1,10 +1,10 @@
 X: 1
 T: Rogues' March
+N: Change: CaptainLanoesQuickMarch.abc
 M: 6/8
 L: 1/4
 Q: 160
 K: Gmaj
-N: Change: CaptainLanoesQuickMarch.abc
 "G" B B/ B/c/d/ | "C" e e<e | "D" d/d/d/ d e/ | "D" d c/ B A/ |
 "G" B B/ B/c/d/ | "C" e e<e | "D" d/e/f/ "G" g/d/B/ | "D" A3/2 "G" G3/2 :|
 "Em" g3/2 "D" f3/2 | "C" e3/2 "D" d3/2 |\