Editing Tritone substitution (section)

===In twelve-bar blues===

One of the most common usages of the tritone substitution is in the [[twelve-bar blues|12-bar blues]]. Shown below is one of the simpler forms of twelve-bar blues.
:{| class="wikitable"
|width="30px"| I<br>C<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| V<br>G<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup>
|}
Next, here is the same 12 bars, except incorporating a tritone substitution in bar 4; that is, with G{{music|b}}<sup>7</sup> substituted for C<sup>7</sup>.
:{| class="wikitable"
|width="30px"| I<br>C<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| {{music|b}}V<br>G{{music|b}}<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| V<br>G<sup>7</sup> ||width="30px"| IV<br>F<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup> ||width="30px"| I<br>C<sup>7</sup>
|}