Who are the 24 elders of Revelation?

In the book of Revelation, who are the 24 elders?

Interpreters identify the elders as either angelic or human. The former view sees them as a special class of 24 angelic administrators closely linked to the four living creatures and forming part of heaven's executive council. Others have considered them as symbolic of redeemed humanity, since they sing, "Thou hast redeemed us..." (5:9). Because of textual uncertainty, the Pronoun "us" should probably (RV and JND) be omitted in verse 9. We should certainly read, "made them kings and priests" and "they shall reign" (verse 20). Therefore the elders are not singing of their own redemption, but concerning that of others. There are, however, some offsetting features. In number, they are 24 (a priestly number, 1 Chronicles 24); in dress, they are in white; in position, they are seated on thrones; in dignity, they are crowned. Significantly, all of these have already been said (chapters 1- 3) of the saints in this present era. We are priests (1:5); as overcomers we are promised white robes (3:5), crowns (3:11), and seats on thrones (3:21). Does not the similarity of these markers indicate that chapters 1-3 portray the saints in testimony upon earth, while chapters 4-5 show the same group in triumph under the figure of elders?

D. Gilliland