Concurring and joined by KAUGER, J.
11 I concur in the Court's opinion with these additional observations.
12 Section 22-159 states that municipalities may support a public school "by the expenditure of municipal revenues for construction or improvement of public school facilities." Municipal sales tax revenue is one type of municipal revenue. See, e.g., 11 O.S.Supp.1992 § 22-154, (sales tax is a municipal tax revenue that may be used as *728payment or security for municipal utility revenue obligations). The Legislature may confer upon a municipality the power to assess and collect a sales tax for the purpose of the municipality. Okla. Const. Art. 10 § 20.1
{ 3 The municipal tax must be imposed by a general law and for a public purpose. Okla. Const. Art. 10 § 14, State ex rel. Brown v. City of Warr Acres, 1997 OK 117, 946 P.2d 1140; Burkhardt v. City of Enid, 1989 OK 45, 771 P.2d 608, 610-611. The statute at issue here is applicable to all school districts, and is thus a general law. Stanolind Pipe Line Co. v. Tulsa County Excise Bd., 1988 OK 248, 80 P.2d 316, 318. The maintenance of a free public school is a duty placed upon the Legislature. Okla. Const. Art. 18 § 1.2 Tax revenue used to maintain a free public school is a tax for a public purpose.
€ 4 The Legislature may not enact statutes that compel a political subdivision to expend its tax revenues for a state function when the political subdivision is funded from ad valo-rem taxes. State ex rel. Jordan v. City of Bethany, 1989 OK 30, 769 P.2d 164; State ex rel. Dept. of Human Services v. Malibie, 1981 OK 18, 630 P.2d 810. However, the Legislature may provide that a municipality may, if it so decides, expend funds for a school district. In 1910 we made the following observation:
What, therefore, the Wetmore Case and the Law Case decided was that the erection of schoolhouses within the corporate limits of a municipality was justly to be regarded as a municipal affair, and that the city, therefore, as such, could create a bonded indebtedness for such like purposes, even though power to do the same thing was, under the general school system of the state, vested in a school district, which, while occupying the same territory as that of the city, was still in point of law a distinct corporate entity. It follows, therefore, that the declaration of this court that the issuing of bonds for the building of schoolhouses by a city is a municipal affair constitutes in no sense a negation of the fact that another corporate entity-the school district-may, under the general school system of the state, do the same thing for the same purpose. Moreover, it should be finally emphasized that the power of a municipality in this regard can only run current with, and never counter to, the general laws of the state touching the common school system. To such general laws, if conflict arises, all municipal charters must be subservient.
As the Legislature of this state did not see fit to confer on cities of the class entitled to frame charters for their own government any power to legislate on matters pertaining to the public school system of the state, it follows that the attempt on the part of the city of Ard-more by its charter to vest such authority in another board than that provided by the general law must fail.
Board of Education of City of Ardmore v. State, 1910 OK 118, 109 P. 568, 566-567, (emphasis added).
We observed in this opinion that both a sehool board and a municipality did, in theory, possess concurrent power, and could provide funds to maintain a school, but that as of 1910 the Oklahoma Legislature had not granted that power to municipalities such as Ardmore. The Legislature has now done so in § 22-159, and a municipality exercising its discretion to expend municipal funds for a school district does not violate the Oklahoma Constitution.
[5 A tax is not a debt. City of Sapulpa v. Land, 1924 OK 92, 228 P. 640, 644. The amount of debt a school district creates is based upon a percentage of the valuation of the taxable property therein. Okla. Const. Art. 10 § 26. Nothing before us suggests that any school district has exceeded this constitutional limitation.
*729[ 6 A governmental subdivision may be the beneficiary of a public trust. Morris v. City of Oklahoma City, 1956 OK 202, 299 P.2d 131. In Arthur v. City of Stillwater, 1980 OK 64, 611 P.2d 637, we discussed a sales tax to be collected by a municipality for the purpose of a public trust that would issue bonds and then use the tax revenue to pay its obligations. Although we explained that a statute required the tax revenue to be placed in the municipality's general revenue fund and then appropriated for the trust, as opposed to going to the trust as an unappropriated amount, we rejected the claim that the trust indebtedness created by the bonds violated Article 10 § 26.of the Oklahoma Constitution. Id. 611 P.2d at 641-642.
17 In sum, nothing in the Oklahoma Constitution prohibits the Legislature from allowing a municipality to raise local tax revenue for the benefit of a school or a municipal improvement trust that then acts to improve a school within that municipality. None of the challenges in this case show either a tax or a public indebtedness that is unconstitutional.
. Okla. Const. Art. 10 § 20:
The Legislature shall not impose taxes for the purpose of any county, city, town, or other mu-picipal corporation, but may, by general laws, confer on the proper authorities thereof, respectively, the power to assess and collect such taxes.
. Okla. Const. Art. 13 § 1:
The Legislature shall establish and maintain a system of free public schools wherein all children of the State may be educated.