The global header allows entering parameters which are common for many regions in the SFZ file. If the same opcode defined in global is also defined in group or region, the group or region setting is used. This means global can be used to set values which are common for most regions in the SFZ file, but if a few regions need something different, they can override the global setting at a lower level. Here is a typical example with two opcodes set at the global header level, some at the group level, and others at the region level. The seq_length (number of round robins) is set to 4 in global, but as the fourth dynamic layer only contains three samples, seq_length is set to for that layer at the group header level.
It is possible to have multiple global headers in one file, at least under ARIA. As with any other header, anything specified under a global header is active until another global header is encountered in the SFZ file.
<global>loop_mode=one_shot seq_length=4 <group>key=36 hivel=31 amp_velcurve_31=1 <region>seq_position=1 sample=kick_vl1_rr1.wav <region>seq_position=2 sample=kick_vl1_rr2.wav <region>seq_position=3 sample=kick_vl1_rr3.wav <region>seq_position=4 sample=kick_vl1_rr4.wav <group>key=36 lovel=32 hivel=63 amp_velcurve_63=1 <region>seq_position=1 sample=kick_vl2_rr1.wav <region>seq_position=2 sample=kick_vl2_rr2.wav <region>seq_position=3 sample=kick_vl2_rr3.wav <region>seq_position=4 sample=kick_vl2_rr4.wav <group>key=36 lovel=64 hivel=95 amp_velcurve_95=1 <region>seq_position=1 sample=kick_vl3_rr1.wav <region>seq_position=2 sample=kick_vl3_rr2.wav <region>seq_position=3 sample=kick_vl3_rr3.wav <region>seq_position=4 sample=kick_vl3_rr4.wav <group>key=36 lovel=96 seq_length=3 <region>seq_position=1 sample=kick_vl4_rr1.wav <region>seq_position=2 sample=kick_vl4_rr2.wav <region>seq_position=3 sample=kick_vl4_rr3.wav