"Come now, and let us reason together, saith the LORD: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool."

1 Peter 3:15  Commanded to give reason of the hope that is within you.

"But sanctify the Lord God in your hearts: and [be] ready always to [give] an answer to every man that asketh you a reason of the hope that is in you with meekness and fear:"

Colossians 4:6  Commanded to be salt.

"Let your speech [be] alway with grace, seasoned with salt, that ye may know how ye ought to answer every man."

Contemporary and Traditional

Used to honor and glorify the Lord
Not used to honor and glorify the Lord

Daniel 3:15-"Now if ye be ready that at what time ye hear the sound of the cornet, flute, harp, sackbut, psaltery, and dulcimer, and all kinds of music, ye fall down and worship the image which I have made;  well:  but if ye worship not, ye shall be cast the same hour into the midst of a burning fiery furnace;  and who is that God that shall deliver you out of my hands."

Country, rock, heavy metal, classical, pop, blue grass, alternative, new age, folk, opera, jazz, blues, hymns, gospel, soul
Ephesians 5:19-psalms, hymns, spiritual songs
Colossians 3:16-psalms, hymns, spiritual songs
Hymns

 humnos {hoom'-nos}
 apparently from a simpler (obsolete) form of hudeo (to celebrate,   probably akin to 103, cf 5667); TDNT - 8:489,1225; n m

 AV - hymn 2; 2

 1) a song in tithe praise of gods, heroes, conquerors
 2) a sacred song, hymn

Spiritual

 pneumatikos {pnyoo-mat-ik-os'}
 from 4151; TDNT - 6:332,876; adj

 AV - spiritual 26; 26

 1) relating to the human spirit, or rational soul, as part of the man
    which is akin to God and serves as his instrument or organ
    1a) that which possesses the nature of the rational soul
 2) belonging to a spirit, or a being higher than man but inferior to God
 3) belonging to the Divine Spirit
    3a) of God the Holy Spirit
    3b) one who is filled with and governed by the Spirit of God
 4) pertaining to the wind or breath; windy, exposed to the wind, blowing

Songs

 ode {o-day'}
 from 103; TDNT - 1:164,24; n f

 AV - song 7; 7

 1) a song, lay, ode

Ireland
Bag pipes

Instruments used in Biblical times

Psalms 42:4-Harp
Psalms 33:2-Harp, psaltery, and an instrument of ten strings
Psalms 71:22-Psaltery, harp
Psalms147:7-Harp
Psalms 149:3-Timbrel, harp
Psalms 150:3-Trumpet, psaltery, harp
Psalms 150:4-Timbrel, stringed instruments, organs
Psalms 150:5-Cymbals, high sounding cymbals
1 Chronicles 13:8-Harps, psalteries, timbrels cymbals trumpets
1 Chronicles 25:6-8-Cymbal, lyres, and harps:  Instruments specified for the temple.
Numbers 10:2-Trumpet

Invented by Jubal

  Genesis 4:21  Harp, flute

Invented by David

  Amos 6:5  Viol

Piano, and a keyboard/ synthesizer/ organ

The American Heritage Dictionary:
Keyboard-
A set of keys as on a piano or typewriter.
Synthesizer-
The combining of separate elements or substances to form a coherent whole.
Organ-
1) A musical instrument consisting of a number of pipes that sound tones when applied with air, and a keyboard that operates a mechanism controlling the flow of air to the pipes.  2)  An instrument designed to imitate the organ electronically.

Lyrics used to address current issues.

Deuteronomy 31:19-22; 30 & 44

Lyrics used to teach and admonish

Colossians 3:16

Music used to organize and to warn

Numbers 10:1-10

It pleases the Lord to praise Him

Psalms 135:3-"Praise the Lord;  for the Lord is good:  sing praises unto his name;  for it is pleasant."
We are commanded to praise the Lord.  (mentioned over 5 times)
Psalms 135:3-"Praise the Lord"
Psalms150:6-"Let every thing that hath breath praise the Lord.  Praise ye the Lord."
Psalms 149:1-"Praise ye the Lord.  Sing unto the Lord a new song"
Jeremiah 20:13-"Sing unto the Lord, praise ye the Lord"
Psalms 100:2-"Serve the Lord with gladness:  come before his presence with singing."
Lyrics used to praise the Lord God  (mentioned over 44 times)
Exodus15:1
Psalms 7:17;  9:2;  21:13;  28:7;  30:4 & 12;  33:2;  44:8;  47:6;  57:7;  61:8;  66:2 & 4;  69:30;  71:22;  98:4;  104:33;  108:1 & 3;  135:3;  146:2;  147:1 & 7;  149:1 & 3;  150:6;  126:2
Romans 15:9 & 11
Ezra 3:10
Jeremiah 20:13;  31:7
Judges 5:3
Nehemiah 12:46
11 Chronicles 7:6;  20:22;  29:30;
Isaiah 42:10
Ephesians 5:19
Colossians 3:16
Revelation 5:8 & 9
Acts16:25

Music alone to praise the Lord

1 Chronicles 23:5

Where to Praise the Lord with Song

Psalms 22:22-"in the midst of the congregation"
Psalms 35:18-"among much people"
Psalms 42:4-"I went with them to the house of God, with the voice of joy and praise, with a multitude that kept holy day"
Psalms 57:9-"I will praise thee, O Lord, among the people"
Psalms 108:3-"I will praise thee, O Lord, among the people:  and I will sing praises unto thee among the nations"
Psalms 149:1-"Praise ye the Lord.  Sing unto the Lord a new song, and his praise in the congregation of saints."
Hebrews 2:12-"I will declare thy name unto my brethren, in the midst of the church will I sing praise unto thee."

A Believer as identified by their works.

Matthew 7:15-18
Mark 3:23-26

Song or music should be new

Psalms 33:3-"Sing unto him a new song;  Play skillfully with a loud noise.

 chadash {khaw-dawsh'}
 from 2318; TWOT - 613a; adj

 AV - new 48, new thing 4, fresh 1; 53

 1) new, new thing, fresh

Psalms 40:3-"and he hath put a new song in my mouth
Psalms 96:1-"O sing unto the Lord a new song"
Psalms 98:1-"O sing unto the Lord a new song"
Psalms 144:9-"I will sing a new song unto thee, O God"
Psalms 149:1-"sing unto the Lord a new song"
Isaiah 42:10-"sing unto the Lord a new song"
Revelation 5:9-"And they sing a new song"  (In Heaven)
Lyrical content should be outstanding
Philippians 4:8-"Finally, brethren, whatsoever things are true, whatsoever things [are] honest, whatsoever things [are] just, whatsoever things [are] of good report; if [there be] any virtue, and if [there be] any praise, think on these things."
1 Corinthians 6:19-20-”What? know ye not that your body is the temple of the Holy Ghost [which is] in you, which ye have of God, and ye are not your own?   6:20For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's."
1 Samuel 2:30-"Wherefore the LORD God of Israel saith, I said indeed [that] thy house, and the house of thy father, should walk before me for ever: but now the LORD saith, Be it far from me; for them that honour me I will honour, and they that despise me shall be lightly esteemed."
Lyrical content should be rooted in Scripture
Joshua 1:8  (Commanded to meditate on God's Word Continuously)
"This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success."
Lyrical content should promote Godly change
.Matthew 5:13Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.Mark 9:49For every one shall be salted with fire, and every sacrifice shall be salted with salt.Mark 9:50Salt [is] good: but if the salt have lost his saltness, wherewith will ye season it? Have salt in yourselves, and have peace one with another.Luke 14:34Salt [is] good: but if the salt have lost his savour, wherewith shall it be seasoned?Colossians 4:6Let your speech [be] alway with grace, seasoned with salt, that ye may know how ye ought to answer every man.

Psalms 98:4-"Make a joyful noise unto the Lord"
Psalms 138:1-"I will praise thee with my whole heart"
1 Chronicles 13:8-"And David and all Israel played before God with all [their] might"
Psalms 149:3-"Let them praise his name in the dance:  let them sing praises unto him with the timbrel and harp."
Psalms 150:5-"Praise him upon the loud cymbals"
11 Chronicles 30:21-"singing with loud instruments unto the Lord":
1 Corinthians 10:31-"Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God."

Sources:

www.goshen.net/pst/  Naves Topical Bible and phrase searches
www.bju.edu/bible/index.html  Greek and Hebrew Lexicon (Strongs)