Who has authority to lead worship?

Are Christian bands worship leaders? Are church choir directors worship leaders? Can anyone lead worship?
          There is a big church not too far from me and routinely, there are christian concerts held there.  There is a common argument that I have heard over the years, that these bands are, in a sense, worship leaders and do these concerts to lead people to the worship of God and it seems that fans are convinced that they are being led into worship and need to be led into worship.  John 4:24, when broken down, states that they who worship MUST CONTINUOUSLY worship in Spirit and Truth.  Furthermore,  Romans 12:1 beseeches the believer to present himself as a living sacrifice.  This verse commands the believer to present themselves as a sacrifice, not have others be the sacrifice for you.

"I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service."

          But is there really such a thing as a worship leader?  Growing up in a Bible-teaching, independent, fundamental and nondenominational church, I was unaware of the title worship leader.  From what I understand and, infinitely more importantly, what the Bible says is that worship is strictly in the heart of a believer. (See post titled "Heart worship") The title worship leader is just that, a title.  The real question is, can a person lead worship, especially if it's in the heart of a believer?   I think it is safe to say that no one on earth can see into the heart of anyone else and so there are a few dangers in calling a person a worship leader.  First, it is inaccurate, since no one can actually lead someone's heart to the worship of God.   Second, a person may begin to, if there is consistency in being referred to as a worship leader, feel as though they are more capable than others in leading worship, which results in the thinking of entitlement to that leader.  Finally, and probably most importantly, over time, the consistency of being called a worship leader, will diminish the true and Biblical appropriateness and importance of PERSONAL worship to each individual believer and the reverential practice of Biblical, corporate worship. The thought of "I need a worship leader so that I can worship" becomes more and more common, and thinking something more and more solidifies it to us and therefore if a person thinks they need a worship leader, over time they'll be convinced of that, that it's true and that it's not up to the individual believer to personally worship the Lord, but that they NEED to be led into worship and only *this* band or *that* person(s) have the capability to do so.
           However,  there is a worship leader for the believer.   The One who knows all.  The One who knows exactly what the worship of the believer looks like, both outwardly, but more importantly, inwardly.  The One who wrote the utmost and authoritative instruction book on worship and the One who does not waver in any Biblical principle of worship.  Of course, I am referring to God Almighty.   God wrote the one and only manual of how HE is to be worshipped.   Others have tried various ways and it has not ended well.  In Leviticus 10:1-2, Nadab and Abihu, though sincere in there desire to please God, were instantly struck dead.  There is no question that because God wrote the book on worship and will only accept worship that is biblical, there should be no question to compromise on the Biblical worship.   So why are there so many different ways that people worship?  The main and number one reason is because of the sin nature.  Sin is innate in man, and has been ever since Adam took of the fruit.  Unfortunately, at the moment of salvation, the sin nature remains in the life of the believer.  Thus the ever present struggle between right and wrong.  One thing that is very evident in all people, to some degree, is selfishness.  Selfishness to always want to do things "MY" way and that "MY" way is the best way or even just that "MY" way is how I want to express myself.  The Lord commands believers to worship in a way that only God will accept.  So, what does God accept? 

See "Acceptable worship" posts.