Opening 6 of the 7 seals (Revelations 6)

Six of the seven seals are opened in this chapter.

I interpret the scroll as the general plan of God, so opening seals that contain it represent things that happen for the plan of God to be fully realized.

I do not think the sequence of these scrolls is chronological, as far as the human concept of time goes.

Seal 1 - a conquering warrior on a white horse.  Note, in contrast to the other horsemen, there is nothing bad about this horseman.  He just is a conqueror.  There is no human death following this horse, unlike the other horseman.  This is important as I think this horseman is identified as Christ later in Revelations.

Seal 2 - a fiery red horseman with power to make men slay each other; many cultures have a "god of war" mythology (ex. Mars, Aries), this is as close as we get to that in the Bible.  We have a horseman of war.

Seal 3 - Black horseman carrying scales.  He pronounces a judgment that basic living food will be too expensive for people to eat, but luxurious items like wine are not too be touched.  To me, this symbolizes poverty and famines resulting simply from economic discrepancies.  Meanwhile, the wealthy who can purchase luxuries will be fine while the poor scrap a living.

Seal 4 - pale horseman.  This one is death itself and can kill a fourth of the earth by war, famine, plague, and beasts of the field.

One fourth of humanity each in the four ways?  It is left unclarified.  But it has a unique power and includes power from the fiery horse (war) and the black horse (famine).

I do not think that these represent onetime unleash of all bad things on earth.  Rather, just a statement of the obvious - all of humanity will die of either war, famine, disease, or some other random death like killed by animals.  But all this must come to pass for God's plan to be fully realized.

Seal 5 - John can see the martyrs of Christ.  They have a special place in the throne of God.

Seal 6 - this creates a cosmological shift.  The star and moon become black and stars fall to earth.  I think this represents a spiritual war in the heavens that created this mess.  Again, I do not think these seals are chronological, but just represent situations that have to happen.  Here, the heaven is at war and stars (angels) fall to earth.  This image is picked up on later in Revelations. 

This heavenly war also had to happen for God's plan to be fulfilled.

The chapter concludes with a multitude of kings, princes, slaves, rich, freeman, etc...hiding in caves from the wrath of the Lamb.  This could span humanity and angels (ex. Prince of Persia, see Dan. 10).  It could be a literal prediction about the Apocalypse, but also could just be a description of how people's hearts will hide from God.