If it is not found in the scripture, wouldn't that make it unscriptural?
"Praise the Lord with harp. Israel was at school, and used childish things to help her to learn; but in these days when Jesus gives us spiritual food, one can make melody without strings and pipes . . . . We do not need them. That would hinder rather than help our praise. Sing unto him. This is the sweetest and best music. No instrument like the human voice." (Spurgeon, Commentary on Ps. 42).
John Calvin: "Calvin is very express in his condemnation of instrumental music in connection with the public worship of the Christian church . . . In his commentary on the thirty-third Psalm he says: `I have no doubt that playing upon cymbals, touching the harp and viol, and all that kind of music, which is so frequently mentioned in the Psalms, was part of the . . . puerile instruction of the law. [But for believers now] musical instruments in celebrating the praises of God would be no more suitable than the burning of incense, the lighting up of lamps, and the restoration of other shadows of the law. The Papists, therefore, have foolishly borrowed this, as well as many other things, from the Jews. Men who are fond of outward pomp may delight in that noise, but the simplicity which God recommends to us by the apostle is far more pleasing to him.'
"In his homily on 1 Sam. xviii. 1-9, he delivers himself emphatically . . . on the subject: What therefore was in use under the law is by no means entitled to our practice under the gospel . . . . Instrumental music, we therefore maintain, was tolerated only on account of the times and the people, because they were as boys, as the Sacred Scriptures speaketh"' (John L. Girardeau, Instrumental Music in the Public Worship of the Church, pp. 163-165).
Ulrich Zwingli, who "had read some of Luther's writings, had become convinced that the New Testament was above all other authority and that the church should be thoroughly purged of everything which did not square with its teachings. Far more than Luther, he wanted to break with the Roman tradition, and to reestablish the church squarely on apostolic foundations . . . . the silence of the Scriptures . . . for Zwingli . . . tended to be a prohibition. Therefore, under his preaching, . . . such Roman practices as Mass, the veneration of images and relics, the confessional, . . . fasting during Lent, clerical celibacy, and the use of organs, were abolished as having no warrant in Scripture" (Richard M. Pope, The Church and Its Culture, p. 355).
John Wesley: "I have no objection to instruments of music in our chapels, providing they are neither heard nor seen" (quoted by Adam Clarke, Clarke's Commentary, IV, 684).