OPINION OF THE COURT
G.B. Smith, J.This action involves the interpretation of a provision in six music royalty contracts detailing the manner in which income from the exploitation of songs must be apportioned between the plaintiff songwriters and defendant Famous Music Corporation. Specifically, the question is whether the contract provision obligates Famous to share with plaintiffs certain tax savings resulting from foreign tax credits. We answer the question in the negative.
*455I.
Ray Evans, Henry Mancini, Johnny Mercer and Richard Whiting are legendary writers of American popular music, particularly music for movies. Famous is a music publisher that Paramount Pictures (Famous’s predecessor-in-interest) established in 1928 to market music from its films. Famous today is a subsidiary of Viacom.
On August 9, 1945, plaintiff Ray Evans entered into a six-month employment contract with Paramount as a staff writer, composer and arranger. Paramount also agreed to pay Evans additional income based on the exploitation of any songs or music he composed pursuant to the contract. On August 31, 1960, Henry Mancini entered into a similar contract with Paramount, the second contract in issue in this case. Mancini’s services under the contract dealt with the movie “Breakfast At Tiffany’s” and its accompanying song, “Moon River,” for which Johnny Mercer wrote the lyrics pursuant to the third contract in this action. Mancini entered into two additional contracts— the fourth and fifth at issue—one for the movie “Hatari,” the other in 1981 with Paramount for the movie “Mommie Dearest.”
Finally, the sixth contract before us, dated November 9, 1959, was entered into between Paramount and the widow and two daughters of Richard Whiting for works he had composed. The contract is a settlement agreement resolving past royalty disputes. The contract is dated November 1959, and covers numerous songs co-authored by Richard Whiting.1
All six contracts contain the following substantially identical provision, which requires that Famous pay the songwriters
“[f|or both words and music an amount equal to fifty per centum (50%) of all net sums actually received by the Corporation with respect to such song or musical composition from any other source or right now known or which may hereafter come into existence (except small performing rights and except as provided in the next following paragraph hereof), less all expenses and charges in connection with administering said rights or collecting such sums . . . and less all deductions for taxes.”
*456Basing their lawsuit on this provision, plaintiffs allege that Famous breached its obligation to reimburse them for their proportional share of tax credits Famous received for the payment of foreign taxes. The complaint alleges that for the years it realized profit for the overseas exploitation of its music, Famous paid taxes to the foreign governments involved and regularly received the benefit of foreign tax credits on its United States tax returns. Plaintiffs claim that under the above-quoted provision, they are entitled to half of the value of the foreign tax credits Famous received.
Famous moved for summary judgment arguing that (1) the plain meaning of the provision does not support plaintiffs’ right to recover the damages they seek; (2) because of past custom and practice in the industry, plaintiffs are not entitled to recovery; and (3) had the parties intended for the plaintiffs to receive such a benefit—which involves a complex calculation dependent on numerous factors—they would have explicitly provided for it in their contracts. In support of the motion, Famous submitted the affidavit of its Executive Vice President of Finance and Administration, highlighting the uncertainty and complexity surrounding the foreign tax credit, and explaining that it was inconsistent with the performance of the parties and industry practice involving similar contracts for publishing companies to credit or share the benefit of any foreign tax credit.
Plaintiffs cross-moved for partial summary judgment, offering the affidavit of a certified public accountant explaining how foreign tax credits operate. Plaintiffs also submitted the affidavit of the Executive Director of the Songwriters Guild of America (SGA), stating that, in 1997, he wrote to Famous and other companies inquiring about the use of foreign tax credits, but received no adequate answer. Famous then responded with the affidavit of a certified public accountant who specializes in the recording/entertainment industry. The accountant was not aware of any music publishing company that interpreted the standard term “all net sums received” or “all net sums actually received” to include the value or benefit of a foreign tax credit. He opined that, in order for a company to make payments relating to tax credits, it would have to agree specifically to do so. He further stated that the calculation of foreign tax credits on a song-by-song basis “would be extremely difficult and impractical, if not impossible.”
Supreme Court granted plaintiffs’ motion for partial summary judgment, holding Famous liable under the contracts. The *457court reasoned that since Famous suffers no loss when a tax payment is credited, “there is no justification for deducting the foreign tax payments from the gross receipts when calculating the ‘net sums’ upon which plaintiffs’ royalty payments are based.” The court found the contractual provisions at issue unambiguous and saw no need to rely on extrinsic evidence. In addition, the court held that the complexities surrounding computation of the foreign tax credits did not relieve Famous of its contractual obligation to share the benefits with plaintiffs. The Appellate Division reversed, concluding that “the benefit of any foreign tax credit was not contemplated by the parties” since the contracts identified the payments plaintiffs were entitled to, but omitted any mention of foreign tax credits. (302 AD2d 216, 217 [2003].) We now affirm.
II.
Unlike many of its trading partners, the United States taxes its citizens and residents on their worldwide income. The foreign tax credit was enacted in 1918 to prevent American companies from being taxed both by the United States and by the foreign country in which the income is generated. Without the credit, United States companies doing business abroad would be at a distinct disadvantage with foreign companies that are not taxed on their foreign income. Generally, where the foreign tax liability is lower than the United States tax liability, the taxpayer will still have a United States tax liability. Where the foreign tax liability is higher than the United States tax liability, the taxpayer will have excess credit. Excess credits may also result from limits on the use of credits.
Application of the foreign tax credit is complex, even by tax standards. As Famous and amicus National Music Publishers’ Association emphasize, there are numerous technicalities surrounding the use of the credit. For example, the credit cannot be used to decrease United States taxes on United States source income (Internal Revenue Code [IRC] [26 USC] § 904 [a]). Credits and foreign source income must be categorized into different so-called “baskets” which may not be combined (IRC § 904 [d] [1]). The credit is elective, and excess credit may be carried back two years and forward five years. These technicalities make the foreign tax credit “one of the most intricate and convoluted features of the entire U.S. tax system” (Kaplan, Federal Taxation of International Transactions, at 81 [West Publishing 1988]; see also Graetz, The David R. Tillinghast *458Lecture, Taxing International Income: Inadequate Principles, Outdated Concepts, and Unsatisfactory Policies, 54 Tax L Rev 261, 264 [2001]). Here, the calculation is even further complicated by inserting Viacom (the entity that would take the credit) into the picture, by classifying royalties as either passive income or general limitation income, by calculating the credit limit allowed under each basket, by carrying over and back excess credits, by potential redeterminations years later, and by a host of other factors.
While a highly complex tax matter, the law issue before us is a simple and familiar one: how should the parties’ contract be interpreted? To phrase it differently, does the obligation to pay half of “all net sums actually received . . . less all deductions for taxes” require Famous to pay half of any tax savings to Famous resulting from the use of the foreign tax credit?
It is well settled that our role in interpreting a contract is to ascertain the intention of the parties at the time they entered into the contract. If that intent is discernible from the plain meaning of the language of the contract, there is no need to look further. This may be so even if the contract is silent on the disputed issue. Illustrative is Greenfield v Philles Records (98 NY2d 562 [2002]), a case involving a contract between recording artists and their producer. There, the issue was whether the producer could use the master recordings for synchronization and other new technologies even though the contract did not explicitly authorize it. Reading the contract as a whole, and consistent with the rules of contract interpretation, we held that the broad grant of ownership rights, without reservation, included the right to synchronization and other newly developed formats. Had the contract been susceptible to more than one reasonable interpretation, it would have been ambiguous.
The contractual provision in the case before us establishes a mechanism for calculating the sharing of income received from the exploitation of songs. The calculation begins with “all net sums actually received” by Famous from “any other source or right now known or which may hereafter come into existence.” From “all net sums actually received,” Famous must deduct certain expenses and taxes, and half of the remainder belongs to the artists.
Plaintiffs argue that the language “from any other source or right now known or which may hereafter come into existence” encompasses a foreign tax credit. This clause addresses the *459means of exploitation. Yet the credit is not income that Famous receives in exchange for the right to use the songs. The credit is given by the United States government because of a tax policy, not in return for the use of songs. While the credit diminishes tax liability, it is not the same as cash or its equivalent.
Plaintiffs also argue that while the contracts specify certain usages that require no payment to the songwriters as well as expenses that must be deducted, they do not exclude benefits from the foreign tax credit. The argument is based on the maxim that the expression of one thing is the exclusion of another. The maxim, however, does not fit neatly within plaintiffs’ interpretation since it would involve placing into the contract a term that was excluded. The argument is a double-edged sword. The contracts provide that the sums specifically provided “represent the total amount which” the songwriters are entitled to. Yet the foreign tax credit is not included. While it is clear that Famous obligated itself to deduct taxes, it is not equally clear that it obligated itself to make payments to the songwriters in the event that the foreign tax credit proved beneficial.
Faced with this ambiguity, we turn to extrinsic evidence for guidance as to which interpretation should prevail. The evidence strongly favors Famous. To begin with, the songwriters have received royalties under these contracts for periods of time ranging from 23 to 59 years, and have never demanded a showing of any credits. When a demand was made, it came in 1997, through a third party, the SGA.2 The contracts are fully capable of being performed—and have been for decades—without the interpretation now sought by plaintiffs. It is no answer that plaintiffs claim to have been unaware that tax credits were being taken by Famous or that Famous was evasive as to whether there were any. Foreign tax credits have existed since 1918.
Industry custom and practice also favors Famous. Plaintiffs did not refute the accountants’ assertions that the language used in the contracts was insufficient to impose on Famous the *460obligation of sharing any benefits resulting from the use of the foreign tax credit with the songwriters. Moreover, when music publishing companies have shared credits with songwriters, they have done so pursuant to an explicit clause.
The industry practice and custom reflects to some extent the generally greater bargaining power of music publishing companies. It also reflects the unlikelihood that a music publisher would assume an onerous obligation without explicitly agreeing to do so, particularly when the obligation is fraught with uncertainty, including how the determination of the benefit should be conducted, how much of the benefit (if any) is attributable to the songwriter, and when and how the benefit would be shared.
In light of the extrinsic evidence, the reasonable interpretation of the contracts before us is that they do not require the sharing of any benefit resulting from defendant’s use of the foreign tax credit.
The reasonable expectation of the parties, the wording of the contracts and the industry practice all demonstrate that the foreign tax credits should not result in additional compensation to plaintiffs.
Accordingly, the order of the Appellate Division should be affirmed, with costs.
. Except for Ray Evans, plaintiffs are successors-in-interest to the songwriters. Famous is the assignee of the rights to exploit the songs under the contracts at issue.
. The record contains several letters between the SGA and Famous. In its initial response, Famous stated that “[a]ny foreign taxes incurred by these subpublishers or withheld from payments due these subpublishers by foreign societies will not even support a claim for foreign tax credit by our company, because these foreign taxes have not been directly imposed or withheld in our name.” In addition Famous argued that even if it owned the subsidiary, the taxes would not be paid on the songwriter’s name so that the songwriter would not be entitled to the credit. The last letter by Famous states that only with respect to Japanese taxes can Famous obtain the foreign tax credit, and even then Famous could not pass along any credit to the songwriters.