We are Israeli activists who support the Palestinian civil society call for Boycott, Divestment and Sanctions (BDS) against Israel's policies of colonialism, occupation and apartheid towards the Palestinian people. We have recently learned of your planned gig in Tel Aviv. We are writing in order to urge you not to come, since your gig will be directly related to Israel's propaganda efforts, at the expense of the Palestinian people. Please hear us out.
Israel's attempts to mask systematic human-rights abuses and decades-long oppression against the Palestinians, rely on its ability to maintain a progressive and democratic image in the eyes of the international community. Israel often goes as far as promoting itself as "the only Democracy in the Middle East". Israel's apartheid policies, however, are inherent even to something as seemingly light-hearted and joyous as a musical gig: Palestinian fans of your music living under the brutal Israeli military occupation of the West Bank or the hermetic siege of the Gaza Strip will be prohibited from coming to Tel Aviv and enjoying your performance. Of course this is only a small example; the hardship entailed in life under occupation goes much further than the denial of access to concerts. All aspects of Palestinian lives are controlled by a foreign occupying army, from the ability to study, work or travel to building permits on their own land.
Here is another example: Palestinian Freedom Riders have recently challenged Israeli segregated buses which they are not allowed to travel on. These buses carry instead Israeli settlers to and from their homes, illegally built on stolen land..Prominent figures, including many musicians and artists, have come here to witness for themselves the treatment of Palestinians living under Israeli rule, and have vowed not to lend their legitimacy to these racist policies.
The Palestinian people are being denied some elementary freedoms: the freedom of movement, the freedom to access their stolen lands and the freedom to protest injustice without facing brutal repression. Those living in the Gaza strip (56% of whom are children) live under a debilitating siege, limiting their access to water, medical supplies, and construction material.
In the East Jerusalem neighborhood of Silwan, 45 minutes away from the scheduled venue, kids are being abducted from their homes, in violation of international law, and taken into violent police interrogations with no access to their parents or a lawyer. All of the aforementioned crimes are taking place only an hour away from your scheduled performance.
Representatives of Palestinian civil society, including over 170 different organizations such as women, academic and workers organizations, have called for a boycott, divestment and sanctions (BDS) campaign against Israel’s policies. International artists are asked not to perform in Israel until it abides by its obligations under international law and reverses these policies.
In a cynical PR attempt to differentiate Tel Aviv from Israel, performances by international artists in TelAviv are used to market the city as a "cool", "enlightened" bubble. This is patently false. Tel Aviv has been built (to be precise, expanded) on the ruins of several Palestinian villages, whose inhabitants had been killed or expelled during the Nakba, the ethnic cleansing that took place in 1948. 
Moreover, Tel Aviv is a pillar of the culture and the economy that sustain Israel's apartheid. Here is a link to a photo of an official poster by the Tel Aviv municipality .
And here is another example, highly relevant to your gig: The owners of the Block Club in Tel Aviv are very proud of the Israeli Ministry of Foreign Affairs use of their name in its promotional videos. The same ministry that "see[s] culture as a propaganda tool of the first rank, and [doesn't] differentiate between propaganda and culture." : (From Hebrew: "The Block club is known as a center of culture and music, where international artists of the first rank perform on a regular basis. A place that's recognized, both in Europe and the USA, as one of the best nightclubs in the world today. So much so that the propaganda branch of the Ministry of Foreign Affairs has chosen it to represent Israel in an official image short to boost tourism." (Hebrew source: ).
Israel's Ministry of Foreign Affairs uses all international gigs in Tel Aviv for such propaganda purposes. The data show clearly that Tel Aviv is not so cool, it`s the financial hub of apartheid and militarism.
Many artists have come to perform here with good will and the intention of using their art as a means to change Israeli public opinion and spread the message of peace. One such example would be that of Roger Waters (please see below). These artists have later come to realize that their performance, as well-meaning as it was, has been hijacked and used to send a green light to the ongoing Israeli policies of oppression.
Some quotes from prominent artists and public figures follow:
-Roger Waters: “In my view, the abhorrent and draconian control that Israel wields over the besieged Palestinians in Gaza, and the Palestinians in the occupied West Bank (including East Jerusalem), coupled with its denial of the rights of refugees to return to their homes in Israel, demands that fair minded people around the world support the Palestinians in their civil, nonviolent resistance. For me it means declaring my intention to stand in solidarity, not only with the people of Palestine, but also with the many thousands of Israelis who disagree with their governments racist and colonial policies, by joining a campaign of Boycott, Divestment, and Sanctions (BDS) against Israel, until it satisfies three basic human rights demanded in international law.”
-Faithless: “We’ve been asked to do some shows this summer in your country and, with the heaviest of hearts, I have regretfully declined the invitation. While human beings are being willfully denied not just their rights but their needs for their children and grandparents and themselves, I feel deeply that I should not be sending even tacit signals that this is either ‘normal’ or ‘ok’.” 
-Archbishop Desmond Tutu of South Africa:“International Boycotts, Divestment and Sanctions against the Apartheid regime, combined with the mass struggle inside South Africa, led to our victory … Just as we said during apartheid that it was inappropriate for international artists to perform in South Africa in a society founded on discriminatory laws and racial exclusivity, so it would be wrong … to perform in Israel.” 
In view of all this, we ask that you reconsider your participation in the whitewashing of Israeli apartheid. Please stand against oppression, and in favour of liberation, against deeply-rooted racism and in favor of justice and equality for all.
We will gladly address any question or comment you may have!
BOYCOTT! Supporting the Palestinian BDS Call from Within
UPDATE: BDS South Africa's Press Release and Open Letter to DJ Black Coffee: