How do I connect staves in a system with a barline?
Choose the Cross Staves Barline tool from the Staves palette. Now drag over the staves you wish to connect starting with the bottom staff, working upward. For example, if you have four staves and you wish to connect the top two staves with a barline and the bottom two staves with a barline, drag over the bottom two staves first, and then over the top two staves. You can break the barline connections by clicking between staves with the eraser tool.