I think that a strong case may be made, in mormal circumstances, for the participation of the laity in any Liturgy. I offer to you Father Schmemann's take on the role of the clergy and laity in the Church (excerpt):
"The Meaning of "Lay"
The words lay, laity, layman come from the Greek word laos which means people. "Laikos," layman, is the one who belongs to the people, who is a member of an organic and organized community. It is, in other words, not a negative, but a highly positive term. It implies the ideas of full, responsible, active membership as opposed, for example, to the status of a candidate. Yet the Christian use made this term even more positive. It comes from the Greek translation of the Old Testament where the word laos is applied ordinary to the People of God, to Israel, the people elected and sanctified by God Himself as His people. This concept of the "people of God" is central in the Bible. The Bible affirms that God has chosen one people among many to be His particular instrument in history, to fulfill His plan, to prepare, above everything else, the coming of Christ, the Saviour of the World. With this one people God has entered into "covenant", a pact or agreement of mutual belonging. The Old Testament, however, is but the preparation of the New. And in Christ, the privileges and the election of the "people of God" are extended to all those who accept Him, believe in Him and are ready to accept Him as God and Saviour. Thus, the Church, the community of those who believe in Christ, becomes the true people of God, the "laos" and each Christian a laikos — a member of the People of God.
The layman, is the one, therefore, who shares in Divine election and receives from God a special gift and privilege of membership. It is a highly positive vocation, radically different from the one we find defined in Webster. We can say that in our Orthodox teaching each Christian, be he a Bishop, Priest, Deacon or just member of the Church is, first of all, and before everything else a layman, for it is neither a negative nor a partial, but an all-embracing term and our common vocation.. Before we are anything specific we are all laymen because the whole Church is the laity — the people, the family, the community — elected and established by Christ Himself.
The Layman Is Ordained
We are accustomed to think of "ordination" as precisely the distinctive mark of clergy. They are the ordained and the laity, the non-ordained Christians. Here again, however, Orthodoxy differs from Western "clericalism," be it Roman Catholic or Protestant. If ordination means primarily the bestowing of the gifts of the Holy Spirit for the fulfillment of our vacation as Christians and members of the Church, each layman becomes a layman — laikos — through ordination. We find it in the Sacrament of Holy Chrism, which follows Baptism. Why are there two, and not just one, sacraments of entrance into the Church? Because if Baptism restores in us our true human nature, obscured by sin, Chrismation gives us the positive power and grace to be Christians, to act as Christians, to build together the Church of God and be responsible participants in the life of the Church. In this sacrament we pray that the newly baptized be:
"an honorable member of God’s Church
"a consecrated vessel
"a child of light
"an heir of God’s kingdom,
that "having preserved the gift of the Holy Spirit and increased the measure of grace committed unto him, he may receive the prize of his high calling and be numbered with the first borne whose names are written in heaven".
We are very far from the dull Webster definition. St. Paul call all baptized Christians "fellow citizens with the saints and the household of God" (Eph. 2:1a). "For through Christ"— he says — ye are no more strangers and foreigners but fellow citizens with the saints... in whom all the building fully framed together growth unto a holy temple in the Lord, in whom ye also are built together for an habitation of God through the Spirit."
The Layman in the Liturgy
We think of worship as a specifically clerical sphere of activity. The priest celebrates, the laity attend. One is active, the other passive. It is another error and a serious one at that. The Christian term for worship is leitourgia which means precisely a corporate, common, all embracing action in which all those who are present are active participants. All prayers in the Orthodox Church are always written in terms of the plural we. We offer, we pray, we thank, we adore, we enter, we ascend, we receive. The layman is in a very direct way the co-celebrant of the priest, the latter offering to God the prayers of the Church, representing all people, speaking on their behalf. One illustration of this co-celebration may be helpful; the word Amen, to which we are so used, that we really pay no attention to it. And yet it is a crucial word. No prayer, no sacrifice, no blessing is ever given in the Church without being sanctioned by the Amen which means an approval, agreement, participation. To say Amen to anything means that I make it mine, that I give my consent to it... And "Amen" is indeed the Word of the laity in the Church, expressing the function of the laity as the People of God, which freely and joyfully accepts the Divine offer, sanctions it with its consent.
There is really no service, no liturgy without the Amen of those who have been ordained to serve God as community, as Church.
And, thus, whatever liturgical service we consider, we see that it always follows the pattern of dialogue, cooperation, collaboration, cooperation between the celebrant and the congregation. It is indeed a common action ("leitourgia") in which the responsible participation of everyone is essential and indispensable, for through it the Church, the People of God, fulfills its purpose and goal."
My emphasis--Second Chance
http://www.schmemann.org/byhim/clergyandlaityinthechurch.html