First, number the shore levels in the bar on the right as 1 to 7, from top to bottom. THen, number the waves from right to left as 1 to 7. When the bar is highlighted, write down the corresponding number. Wait for all seven notes, then click the corresponding numbers on the waves.
After getting your four crystals, you need to transport them in the portal. Place crystals 1 and 3 (numbered in the order that they appear), pass them, and put crystal 1 in the portal. Return with crystal 3 and switch it with crystal 2 and 4. Pass them and put them in the portal. Take crystal 1 and go back, then take crystals 1 and 3 in the portal. Another crystal will appear there. Click on crystals 1 and 3 and you are done.